February 14, 2000, at 10:33 AM EST the NEAR spacecraft was successfully inserted into orbit around 433 Eros, becoming the first artificial satellite of an asteroid. Just over an hour later, NEAR pointed its camera at the asteroid and took this picture from a range of 210 miles (330 km) above the surface. Mission navigators and operators will use this image and others to be taken later to triangulate on landmarks on the asteroid's surface, precisely measuring position of the spacecraft to plot NEAR's course.

Features as small as a 100 feet (30 meters) across can be seen. This view shows the 3-mile (5-kilometer) impact crater which the spacecraft has spied for over a week during its approach. The two smaller craters superimposed on its rim are each about 1.2 miles (2 kilometers) across. An enormous boulder a full 170 feet (50 meters) in size sits on the large crater's floor. Other key features of the surface are shallow subsurface layering exposed near the tops of crater walls, and shallow grooves crossing the surface and cutting the crater's rim.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02464: NEAR Historic First Image from Eros Orbit sur le site de la NASA.

PIA03133: On Eros' Slopes

NEAR Shoemaker took this picture of the interior wall of a large crater on January 9, 2001, from an orbital altitude of 35 kilometers (22 miles). Like many steep slopes on Eros, this area is mottled with downward-oriented brightness streaks. The streaks are thought to be exposed subsurface material that hasn't been altered by the solar wind and micrometeorite impacts. The whole scene is about 0.8 kilometers (0.5 miles) across.

PIA02932: Salt Water Taffy

NEAR Shoemaker's camera captured this oblique view of the wall of Eros' saddle on June 19, 2000, from an altitude of 51 kilometers (32 miles). Curvature in the wall, combined with brightness banding in the left portion of the picture, give the surface a surreal, taffy-like appearance. The bright patches may originate from exposure of subsurface material that hasn't been darkened by small impacts and solar wind. These patches are juxtaposed, at the bottom left-center of the picture, with a mysterious dark apron surrounding a 150-meter (490-foot) diameter crater. The whole scene is approximately 1.2 kilometers (0.7 miles) top to bottom.

PIA03148: Final Eros Images: Last, Closest Image of Eros

This is the last image of asteroid 433 Eros received from NEAR Shoemaker. Taken from a range of 120 meters (394 feet), it measures 6 meters (20 feet) across. What we can see of the rock at the top of image measures 4 meters (12 feet) across. The streaky lines at the bottom indicate loss of signal as the spacecraft touched down on the asteroid during transmission of this image.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03148: Final Eros Images: Last, Closest Image of Eros sur le site de la NASA.

PIA02463: NEAR Approach to Eros - 12 panel rotation sequence

On February 12, two days before NEAR's insertion into orbit around Eros, during a five-hour time span the spacecraft's Multispectral Imager recorded these pictures of the asteroid spinning on its axis. This view, looking down toward the rocky body's north pole, is generally similar to sequences taken on February 6, 10, and 11. But the spacecraft was much closer to Eros (about 1,800 kilometers or a little over 1,100 miles), so the pictures are much sharper.

Features as small as a 590 feet (180 meters) wide can be seen. The most prominent, sharp-rimmed impact crater is on the opposite side of Eros from a huge, hollowed-out gouge, which may also have been caused by an impact. Between these features, and towards the ends of the "fat banana" shape of Eros, the asteroid's surface is covered with smaller craters.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02463: NEAR Approach to Eros - 12 panel rotation sequence sur le site de la NASA.

PIA03134: Bright Crater Wall

NEAR Shoemaker captured this image on January 11, 2001, while orbiting 38 kilometers (24 miles) above Eros. Material on the inner wall of the crater in the center of the image is brighter than the surrounding regolith and is thought to be subsurface material exposed when overlying, darker regolith slides off. The whole scene is about 1.2 kilometers (0.7 miles) across.

PIA03146: Final Eros Images: Range 700 meters (2,300 feet)

NEAR Shoemaker's image of asteroid 433 Eros taken from a range of 700 meters (2,300 feet). The image is 33 meters (108 feet) across. The large, oblong rock casting a big shadow measures 7.4 meters (24 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03146: Final Eros Images: Range 700 meters (2,300 feet) sur le site de la NASA.

PIA03141: The Environs of NEAR Shoemaker's Landing Site

This image mosaic of Eros' southern hemisphere, taken by NEAR Shoemaker on November 30, 2000, offers a long-distance look at the cratered terrain south of where the spacecraft will touch down on February 12, 2001. In this view, south is to the top and the landing site itself is just into the shadows, slightly left of center. The length of the asteroid is 33 kilometers (21 miles).

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03141: The Environs of NEAR Shoemaker's Landing Site sur le site de la NASA.

PIA03108: The Many Faces of Eros

This montage shows structural features on Eros obtained by NEAR Shoemaker from several different orbits. Any underlying, deep-seated structures probably formed as a result of large impacts to the asteroid's surface, in the same way that a car windshield fractures when it is hit by a stone. Later, movement of regolith may have modified the structure's surface expressions.

Troughs -- Shallow troughs (top left) are found within the saddle region of Eros and are very closely aligned. A large flat-floored trough (bottom left) is found in the saddle.

Pits -- The top right image shows a chain of pits, most likely the result of loose regolith (impact-derived soil) draining into a crack on the asteroid's surface.

Ridges -- At center, right is the ridge that winds from Eros' saddle area around the north pole down to the 5.3-km crater.

Fractures -- The center image shows the region where the ridge ends. The ridge comes up from the bottom of the image and, near the center, appears to turn into a set of small fractures.

Grooves -- The bottom, right image shows grooves on a relatively smooth area of Eros' western hemisphere. These are evenly spaced and some look like they have raised rims.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03108: The Many Faces of Eros sur le site de la NASA.

PIA02909: Looking Down

NEAR Shoemaker photographs Eros under a variety of lighting and viewing geometries suited to different science objectives. Taken with the Sun high in the sky, images with few shadows are best for mapping the color properties of the surface. Conversely, images taken from directly above a surface with oblique illumination are best for seeing landforms, because shadowing highlights the subtle shape changes on the asteroid's surface.

This image was taken at the latter geometry on May 11, 2000, from an orbital altitude of 52 kilometers (33 miles). The whole scene is about 1.8 kilometers (1.1 miles) across, and shows features as small as 4 meters (13 feet). The rounded nature of the landforms results from formation of small impact craters over the eons. Sharp topography is eroded away by this process, and the surface is blanketed and smoothed by the fragmental debris, or "regolith." The large boulders scattered throughout the scene are the largest fragments of the rocky regolith.

PIA02489: NEAR: From Planning to Data Analysis

Planning and acquiring observations from NEAR's Near-Infrared Spectrometer (NIS) is a complex process that requires a detailed understanding of the strange shape and the rotational state of Eros. On February 13-14, 2000, just before insertion into Eros orbit, NEAR passed between Eros and the Sun. This geometry is called a low phase angle. It is optimum for spectroscopic observations, so at that time NIS obtained some of its most valuable data. To plan these activities in the preceding months, the NEAR science team developed a series of global NIS observation sequences like the one depicted in the left image. Here, NIS was instructed to scan its mirror back and forth across Eros while the spacecraft did a slow slew from top to bottom. The image shows the predicted coverage as viewed from directly over the north pole of a computerized "shape model" of Eros. Many such observation sequences were performed flawlessly on the spacecraft during the "low phase-angle flyby," and the highest-quality spectra were combined to show the resulting NIS coverage of Eros in the map on the right. The green and red regions show areas at high northern latitudes with the best coverage by NIS. Analysis of the NIS spectra is providing clues about the mineralogy and composition of Eros, and perhaps its early history and evolution.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02489: NEAR: From Planning to Data Analysis sur le site de la NASA.

PIA02900: Back in the Saddle Again

Again and again, NEAR Shoemaker's imager is being directed at the "saddle region" of Eros, to observe this feature under the widest variety of lighting conditions. This image of the saddle was taken March 22, 2000, from a range of 208 kilometers (129 miles). Generically speaking, a saddle is a low ridge connecting two mountains. The definition does not include an explanation for the origin of the curvature. Similarly, on Eros, the term "saddle region" is a description of a physical feature and doesn't imply any particular origin.

Perhaps the most frequently asked question about Eros' surface is, "What is the origin of the saddle?" Was it formed as a spallation scar resulting from the impact that created the large 5.5-kilometer (3.4-mile) diameter crater on the opposite side of the asteroid? To determine its origin will take time. Right now, the southern part of the feature is still in shadow. Over the next few months, as the Sun moves south in Eros' sky, the whole saddle will become visible. As NEAR Shoemaker continues to take more and more pictures of the saddle region, we will be better able to answer key questions about this feature.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02900: Back in the Saddle Again sur le site de la NASA.

PIA02487: Glimpses into Eros' Shadows

This image mosaic, showing Eros' saddle and a shadowed feature to its left, was taken on March 3, 2000 from a distance of 204 kilometers (127 miles). In this picture features as small as 20 meters (65 feet) across are visible. This is the best view to date of this area. The sun is coming from the northeast illuminating a shadowed feature that consists of three large craters situated adjacent to each other. The two largest are each about 4-5 km (2-3 miles) across. Because the sun is very low with respect to these craters, even small topographic features cast long shadows, making them easier to see. As a result, several boulders on the crater walls can be distinguished, ranging from about 50 to 100 meters in diameter. The saddle (on the right of the mosaic) is relatively smooth with few impact craters, and has several grooves running across it. At the top of the saddle are several curved grooves that are brighter than the surrounding surface. Unusual brightness patterns are also visible in the crater at the top left of the mosaic. The walls of the crater appear to be more reflective and its floor less reflective than nearby parts of the asteroid.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02487: Glimpses into Eros' Shadows sur le site de la NASA.

PIA03106: Eros' Angular Eastern End

NEAR Shoemaker captured this view of Eros' eastern hemisphere on September 9, 2000, from an orbital altitude of about 100 kilometers (62 miles). The spacecraft is in a high enough orbit to "see" the overall global shape of Eros as it did earlier in the mission, but from a different perspective. The eastern end's blocky, angular appearance likely results from large impacts suffered by Eros early in its history. The image also shows several long ridges and a cluster of boulders. The entire scene is about 4 kilometers (2.5 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03106: Eros' Angular Eastern End sur le site de la NASA.

PIA02480: The Sculptured Surface of Eros

NEAR takes several images mosaics of Eros daily for purposes of navigating the spacecraft. The one shown here was taken February 29, 2000, from a range of 289 kilometers (180 miles). It shows features as small as 30 meters (100 feet) across. All of the mosaics show the same territory over and over, but changes in lighting plus the gradual decrease in the spacecraft's range to the surface are both constantly bringing out new details.

The very oblique illumination in this mosaic is ideal for bringing out small landforms. Many parts of the asteroid have "grooves," linear troughs about 100 meters (330 feet) wide and several kilometers long. Similar features have also been observed on other asteroids such as Gaspra, and they are especially numerous on Mars' moon Phobos. Their origin isn't completely understood, but formation of the grooves probably involves fracturing of the asteroid's subsurface in some way.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02480: The Sculptured Surface of Eros sur le site de la NASA.

PIA02907: Light and Shadow

Eros' irregular shape creates interesting and beautiful scenes where the Sun shines obliquely on the surface. In the absence of an atmosphere, and hence no secondary illumination reflecting from atmospheric molecules, shade appears nearly as black as space.

This image, taken from the NEAR Shoemaker spacecraft on May 2, 2000, from an orbital altitude of 50 kilometers (31 miles), shows one of the more telling and yet comical combinations of light and shadow. The entire scene is about 1.8 kilometers (1.1 miles) across. High spots near the edges of shadows, like the 35-meter (115-foot) diameter boulder just below the center of the frame, seem almost to "float" above the surface. With a little imagination, the shadow dominating the right side of the frame could be seen as a small, long-eared terrier bending over to sniff his dinner!

PIA03117: Eros Map and Place Names

This simple cylindrical projection of an image mosaic of Eros is labeled with proposed names for most of the larger features on the asteroid. Because the images in the mosaic cover an irregularly-shaped object viewed under greatly varying lighting and viewing geometries, it is not possible to match boundaries of images perfectly. The names shown here permit those studying the asteroid to have a consistent "geography" for reference. The theme of the names is famous lovers from history and fiction, taken from different cultures. The name of the largest feature, Himeros, comes from Greek mythology for personification of the longing of love and an attendant of Eros.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03117: Eros Map and Place Names sur le site de la NASA.

PIA02491: Eros Surface Morphology

On March 10, 2000, this image of Eros was acquired by the imager on the NEAR Shoemaker spacecraft, from a range of 206 kilometers (127 miles). The area shown in the image is 10 kilometers (6.2 miles) across, and the smallest detail visible is 20 meters (65 feet) across. Here, the spacecraft was over the shaded interior of the "saddle," looking over the north polar region to the limb. The shadowing at the upper right is due to oblique lighting. The narrowness of the illuminated part of Eros in the center of the frame results from viewing the narrow "waist" of Eros' irregular peanut-like shape.

This image is from one of a large number of imaging sequences acquired during the first of two "200-kilometer" (124-mile) orbits. The second 200-kilometer orbit, in autumn 2000, will provide similar views of southern latitudes. The purpose of many of the sequences in this orbit is to view the northern and equatorial latitudes of the asteroid under conditions similar to those at the time of this image, looking straight down on a part of the surface (called a "low emission angle") while the surface is obliquely illuminated (called a "high incidence angle"). The resulting views bring out surface morphology and are crucial to making a global map of Eros.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02491: Eros Surface Morphology sur le site de la NASA.

PIA02911: Rock Bands

Images of Eros returned by NEAR Shoemaker show that many of the asteroid's craters have striking brightness patterns on their walls. This image, taken May 16, 2000, from an orbital altitude of 50 kilometers (31 miles), shows these brightness patterns at high spatial resolution. The whole scene is about 1.9 kilometers (1.2 miles) across, and shows features as small as 4 meters (13 feet). The brighter materials are several percent more reflective than their surroundings.

PIA03110: An Ancient Ridge

This mosaic of four images -- taken by NEAR Shoemaker on September 21, 2000, from about 100 kilometers (62 miles) above Eros -- covers part of the asteroid's southern hemisphere, southwest of the large, 5.3-kilometer (3.3-mile) diameter crater. The ridge that trends from upper left to lower right is among the older features on Eros, as evidenced by the large number of superimposed impact craters. The whole scene is approximately 11 kilometers (7 miles) from top to bottom.

PIA02496: Boulders, Boulders, Boulders

One of the most striking features in NEAR Shoemaker images of Eros' surface is the abundance of very large boulders. This image of the southwestern part of the saddle region, taken March 6, 2000, from a range of 201 kilometers (125 miles), shows a particularly boulder-rich part of the surface. Many of the huge rocks are 50 meters (164 feet) or more in diameter. They are believed to be fragments of Eros' native rock, shattered over the eons by formation of impact craters. The impacting projectiles themselves were pulverized by the impact process and survive only as fine debris mixed into the regolith.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02496: Boulders, Boulders, Boulders sur le site de la NASA.

PIA02498: Eros'North Pole

For much of the past five weeks, imaging activities on the NEAR Shoemaker spacecraft have focused on the high northern latitudes of Eros. The point at which the Sun is directly overhead - known as the "subsolar point" - has been steadily moving from Eros' northern regions toward the equator as the asteroid's seasons progress. As this happens, the northern hemisphere is illuminated less and less, and previously dark southern latitudes progressively come into view. In this image, taken March 19, 2000, from a range of 205 kilometers (127 miles), the asteroid's north pole is in the upper right of the frame. The whole scene is 7.4 kilometers (4.6 miles) across.

PIA03119: Eros Closest Approach Mosaic

This image mosaic was taken in the early hours of October 26, 2000, as NEAR Shoemaker made its low-altitude flyover of Eros. At the time of closest approach, the camera was looking at a region just 6.4 kilometers (4 miles) away. Much of the surface is covered in rocks of all sizes and shapes, set on a gently rounded surface. Other regions are smooth, suggesting accumulation of fine regolith. The smallest rocks seen are about 1.4 meters (5 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03119: Eros Closest Approach Mosaic sur le site de la NASA.

PIA02964: Rocky Hollow Picture Show

NEAR Shoemaker images of Eros' saddle region show landscapes that couldn't differ more from what one might have expected for an ancient, crater-battered body. Early images of the northern part of the saddle stunned mission scientists with their abundance of boulders and lack of craters. Recent images of the southern part of the saddle, now well illuminated having emerged from the southern hemisphere's long night, continue this fascinating picture show. This picture, taken August 3, 2000, from an orbital altitude of 50 kilometers (31 miles), shows a region about 1.4 kilometers (0.9 miles) across. Boulders as small as 8 meters (26 feet) across are visible. In this part of the saddle, small patches of brighter regolith also occur among the rocks.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02964: Rocky Hollow Picture Show sur le site de la NASA.

PIA02951: Eros: Closest View Yet! (36 km altitude)

In NEAR Shoemaker's long-awaited close-up images of Eros, the asteroid's small-scale features are revealing their fascinating diversity. This picture, taken July 8, 2000, from an orbital altitude of 36 kilometers (22 miles), shows a variety of differently shaped boulders. Some are nearly round, whereas others are elongated or even blade-shaped. Such varied shapes might arise from differences in the strength and fracturing of preexisting rock. The whole scene is 1.4 kilometers (0.8 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02951: Eros: Closest View Yet! (36 km altitude) sur le site de la NASA.

PIA02956: Eros' Littered Surface from Low Altitude

NEAR Shoemaker's incredibly detailed images from the low orbit around Eros continue to surpass the expectations of the mission team. This picture, taken July 24, 2000, from an orbital altitude of 36 kilometers (22 miles), shows a region about 900 meters (3,000 feet) across. Some of the largest boulders in the scene, such as the broken one at the upper left, show angular shapes. Many smaller boulders litter the scene; the smallest ones visible here are about 6 meters (19 feet) across.

Regolith seems to have banked up against several rocks. In some places, like the large crater below the center of the picture, regolith also appears to have filled, or "ponded," in low spots.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02956: Eros' Littered Surface from Low Altitude sur le site de la NASA.

PIA02924: Mosaic of Eros' Northern Hemisphere

NEAR Shoemaker obtains the best views of subtle details in Eros' landforms when the spacecraft's imager looks straight down at the surface, and the Sun illuminates the surface at a very low angle. Such lighting brings out even tiny undulations in the surface and makes features stand out sharply. This image -- acquired June 6, 2000, from an orbital altitude of 49 kilometers (30 miles) -- was taken under those ideal conditions. The landscape is textured by low ridges and grooves running from left to right, with numerous boulders sprinkled on them. The whole scene is 1.4 kilometers (0.9 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02924: Mosaic of Eros' Northern Hemisphere sur le site de la NASA.

PIA03125: Eros' Battered Surface

NEAR Shoemaker captured this image of Eros on November 28, 2000, while taking a color flyover movie from 193 kilometers (120 miles) away. This particular view simultaneously shows several key indicators of the battering Eros' surface has sustained over the eons. Most obvious are the countless craters, some barely big enough for the camera to see. Less obvious are the signs of a layer of fragmental debris, or regolith, blanketing the surface. Among them are the rounded horizon, the boulders visible in the distance, and the bright patches of exposed subsurface material on steep slopes. This scene is approximately 6.6 kilometers (4.1 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03125: Eros' Battered Surface sur le site de la NASA.

PIA02472: Eros Image Mosaic, looking north

This image mosaic of Eros was taken by the NEAR spacecraft on Feb. 18, 2000 from a range of 224 miles (361 kilometers). The smallest detail visible on the surface is about 115 feet (35 meters) across. At the time the spacecraft was over the shadowed southern hemisphere, looking north at a crescent Eros. Although this view of Eros is similar to others that have been returned, the coverage at different illumination and viewing geometries provides important information on the shapes of landforms.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02472: Eros Image Mosaic, looking north sur le site de la NASA.

PIA02958: The Impact of Cratering

Impacts to Eros slowly and continually modify the appearance of the asteroid's surface. This NEAR Shoemaker image taken July 23, 2000, from an orbital altitude of 38 kilometers (24 miles), shows the effects around a crater that is nearly a mile (1.6 kilometers) across. An impact excavated a huge gouge, and caused some of the excavated material to form a thin cover on parts of Eros. The fastest-moving fraction of the crater's ejecta (traveling at more than several meters per second) escaped Eros, whereas slower-moving material eventually returned to the surface. The boulders in the foreground, about 15 meters (50 feet) across, are typical of the largest pieces in a crater's ejecta. Over time the surface layer slid off the crater's walls to expose brighter material from below, which has not yet been darkened by space weathering. The picture shows a region about 1 kilometer (0.6 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02958: The Impact of Cratering sur le site de la NASA.

PIA03122: Now and Then

During NEAR Shoemaker's first look at Eros, in December 1998, the Sun was high in Eros' southern hemisphere, as it is now. One big difference between then and now is the spatial resolution of the images, which is much better now because the spacecraft is closer. This image was taken November 17, 2000, from a mapping orbit of 195 kilometers (121 miles). The part of the asteroid shown is in the southern hemisphere, at the eastern edge of the saddle region, which covers the bottom half of the picture. This part of the saddle is covered in boulders and patches of bright surface material. In the view from 1998 (inset) -- taken from more than 3,800 kilometers (2,400 miles) away, with the asteroid in a similar orientation -- only a large bright patch could be discerned.

PIA02475: Eros' Bland Butterscotch Colors

These color images of Eros was acquired by NEAR on February 12, 2000, at a range of 1800 kilometers (1100 miles) during the final approach imaging sequence prior to orbit insertion. A five and one-half hour long sequence of images covering visible and infrared wavelengths was taken at that time, to provide a global overview of the color and spectral properties of the asteroid. The images show approximately the color that Eros would appear to the unaided human eye.

Eros' subtle butterscotch hue at visible wavelengths is nearly uniform across the surface. Two days after these images were taken, mapping by NEAR's infrared spectrometer showed that Eros exhibits a great deal more variety at longer wavelengths. These variations could be due to differences in texture or composition of the surface. Both NEAR's multispectral imager and infrared spectrometer will be used extensively during the month of March to map Eros' color and spectral properties from an altitude of 200 kilometers (120 miles). The images to be returned will show details as small as 20 meters (68 feet) across, providing a new perspective on the asteroid's many fascinating landforms discovered so far by NEAR.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02475: Eros' Bland Butterscotch Colors sur le site de la NASA.

PIA02923: Mosaic of Eros' Northern Hemisphere

While NEAR Shoemaker orbits Eros, the asteroid appears too large for the camera's field of view. In order to get a complete view of the surface from a particular vantage point, several images are mosaiced. To do this, the digital images returned by the spacecraft are draped over a computer model of the asteroid's shape.

This spectacular view -- looking down on the north polar region -- was constructed from six images taken February 29, 2000, from an orbital altitude of about 200 kilometers (124 miles). This vantage point highlights the major physiographic features of the northern hemisphere: the saddle seen at the bottom; the 5.3-kilometer (3.3-mile) diameter crater at the top; and a major ridge system running between the two features that spans at least one-third of the asteroid's circumference.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02923: Mosaic of Eros' Northern Hemisphere sur le site de la NASA.

PIA03107: Under the Saddle

NEAR Shoemaker took the four images in this mosaic on September 9, 2000, from an altitude of about 100 kilometers (62 miles). NEAR Shoemaker's current orbit affords a global look at Eros much like earlier in the mission, but from a more southerly perspective. The top of this mosaic shows Eros' saddle, and curving around at upper right is the large bright-and-dark groove . The bright curved feature is a broad topographic rise separating the saddle region from the most boulder-rich area on the asteroid .

PIA02481: Large Crater on Eros

This image mosaic of the large crater at Eros' center was taken on March 3, 2000 during an optical navigation imaging sequence from a range of 127 miles (204 kilometers). This same area was imaged following orbit insertion at a range of approximately 210 miles (330 kilometers) on February 14th. This picture resolves features as small as 65 feet (20 meters) across compared to the resolution of 100 feet (30 meters) in the earlier image. The shadow cast by the boulder near the floor of the crater is now visible. The walls of the crater display some distinctive variations in their albedo or reflectivity. The upper part of the walls tend to be bright, while the lower portions of the walls and the crater floor show patches of darker or less reflective materials. These albedo patterns are also visible on other crater walls. To the right of the large crater, two sets of closely spaced orthogonal grooves are visible.

PIA02906: Horizon View

This image of Eros, taken from the NEAR Shoemaker spacecraft on May 2, 2000, from an orbital altitude of 52 kilometers (32 miles), shows a view toward Eros' horizon. The section shown is about 1.8 kilometers (1.1 miles) across. This particular view provides a snapshot of three of the most common types of features seen on the asteroid: craters whose rims have been rounded by erosion due to smaller impacts and blanketing by the impact debris, or regolith (impact debris); variations in the brightness of material on the walls of the craters; and a scattering of boulders ranging in size from nearly 100 meters (328 feet) down to about 8 meters (26 feet).

PIA02901: Eros Up Close

Since April 11, the NEAR Shoemaker spacecraft has orbited Eros at an altitude of 100 kilometers (62 miles) from the asteroid's center. Images acquired from this orbit will be used to make a high-resolution map of the illuminated portion of the asteroid. Each spot on the surface will be imaged under a variety of lighting and viewing conditions to bring out different features.

In this image, taken April 17, 2000, from a height of 101 kilometers (63 miles), the shadows highlight small-scale surface features. The surface is pockmarked with craters ranging in size up to the 2.8-kilometer (1.74-mile) diameter crater in the center of the image. The smallest craters which can be resolved are about 20 meters (65 feet) across. In lower right corner of the image, 20-meter boulders can be seen that were not evident in images from higher altitudes.

PIA02488: A Trio of Craters on Eros

The Near Earth Asteroid Rendezvous (NEAR) spacecraft snapped the image on the left (Image of the Day Feb. 13, 2000 B) during its approach to Eros on Feb. 11, 2000, from a range of 2590 kilometers (1,609 miles). This image shows a heart-shaped depression about 5 km (3 miles) long. The image mosaic on the right was taken from 204 km (127 miles) on March 3, 2000 and reveals that the mysterious heart-shaped feature is actually 3 separate craters. The oblique lighting conditions and low resolution of the earlier image created the illusion of a heart shape.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02488: A Trio of Craters on Eros sur le site de la NASA.

PIA03109: A Hint of Structure

This is a mosaic of four images taken by NEAR Shoemaker on September 5, 2000, from about 100 kilometers (62 miles) above Eros. The knobs sticking out of the surface near the top of the image surround a boulder-strewn area (featured as the Image of the Day for April 4, 2000) and are probably remnants of ancient impact craters. The very faint grooves that run diagonally across the surface in this image may have formed during a collision between the asteroid and a smaller body.

PIA02908: The Saddle Wall

One of the most interesting features on Eros is the "saddle," an indentation in the asteroid's peanut-like shape. The low density of impact craters inside the saddle indicates that geologic processes had modified the region relatively late in Eros' history.

The NEAR Shoemaker spacecraft captured this image of the inside of the saddle on May 5, 2000, from an orbital altitude of 52 kilometers (32 miles). The whole scene is about 1.8 kilometers (1.1 miles) across, and the image shows features as small as 4 meters (13 feet) across. The bright feature running from the top to the bottom of the image is a steep, Sun-facing slope. In some places it appears to be an escarpment, while near the center of the image it appears as an inside wall of a 200-meter (656-foot) wide trough. The boulder in the upper right of the image is nearly 40 meters (131 feet) across.

PIA03140: Boulderado

PIA03147: Final Eros Images: Range 250 meters (820 feet)

NEAR Shoemaker's image of asteroid 433 Eros taken from a range of 250 meters (820 feet). The image is 12 meters (39 feet) across. The cluster of rocks at the upper right measures 1.4 meters (5 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03147: Final Eros Images: Range 250 meters (820 feet) sur le site de la NASA.

PIA02934: The Southern Saddle (Mosaic)

NEAR Shoemaker captured the southern part of Eros' saddle in this mosaic of seven images taken May 17, 2000, from an altitude of 49 kilometers (30 miles). The two most conspicuous features in this part of the saddle are the wide, curved trough and the bright area in the lower left section. The trough is nearly 400 meters (1,300 feet) across at its widest point, and its curved shape is quite unlike the narrower, linear grooves found elsewhere on Eros. The bright region at the lower left was conspicuous even from thousands of kilometers away, when NEAR Shoemaker took the first pictures of it in December 1998.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02934: The Southern Saddle (Mosaic) sur le site de la NASA.

PIA02462: NEAR Road to Eros

This montage shows a selection of images of the asteroid 433 Eros that were acquired from the NEAR spacecraft over three weeks from January 22 through February 12, 2000, as the spacecraft's distance from its target shrank from 18,000 to 1260 miles (29,000 to 2025 km). As the spacecraft closed in on its target, the resolution of the images increased from 1.7 to 0.12 miles (2.8 to 0.19 km) per pixel. At 20x8x8 miles in size (33x13x13 kilometers), Eros is the second largest near-Earth asteroid and spins on its axis once every 5 hours, 16 minutes.

During the early stages of NEAR's approach, Eros appeared as a small blob only a few pixels across. The apparent size of Eros and the resolution of the pictures increased continuously, at first only slowly and later dramatically day by day until, on February 9, the level of detail visible exceeded that during NEAR's first flyby of Eros on December 23, 1998. In the last images shown here, details of Eros's surface have become visible. Heavy cratering has pockmarked the irregular asteroid's surface. One side is dominated by a scallop-rimmed gouge, and the opposite side by a conspicuous, raised-rimmed crater.

PIA03135: Regolith

This picture of Eros, taken by NEAR Shoemaker on January 14, 2001, from an orbital altitude of 38 kilometers (24 miles), visually summarizes the unexpected nature of small-scale features on the asteroid's surface. Armed with a prejudice that the Moon's surface is typical of an airless body, one might expect Eros' surface to be dominated at all scales by craters. Instead, in an image like this, which shows features as small as 6 meters (19 feet) across, the surface is dominated by a blanket of regolith. Boulders litter the landscape, and the smallest craters are obscured - at times almost beyond recognition. Many of the low spots are extremely flat, and appear infilled. The whole scene is about 1.1 kilometers (0.7 miles) across.

PIA02465: Eros: The first look from orbit

In the first hours after NEAR's insertion into Eros orbit (February 14, 2000), the spacecraft's camera took these images from a range of 210 miles (330 km) above the surface. The many craters visible serve as landmarks for navigating the spacecraft. Mission operators observe such features from different angles, and use triangulation to calculate NEAR's position relative to the surface of Eros. The changes in position over time help to plot NEAR's course in orbit.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02465: Eros: The first look from orbit sur le site de la NASA.

PIA03132: An Eraser Mark on Eros

NEAR Shoemaker captured this amazing picture of adjacent regions in different states of surface degradation on January 7, 2001, from an orbital altitude of 35 kilometers (22 miles). The upper half and lower right parts of the image show surfaces with "typical" rounded craters and large boulders. However, the abruptly edged swath extending from lower left to middle right is remarkably more smooth, subdued, and lacking in small-scale detail of any type -- almost as if Eros had been altered by a giant eraser. The whole scene is about 1.4 kilometers (0.9 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03132: An Eraser Mark on Eros sur le site de la NASA.

PIA02933: Southwest of the Big Crater (Mosaic)

This mosaic of eight images -- which NEAR Shoemaker snapped on May 14, 2000, from an altitude of 50 kilometers (31 miles) -- covers the region southwest of Eros' large, 5.3-kilometer (3.3-mile) diameter crater. The bright patches at upper right are relatively freshly exposed regolith on the inside wall of the crater. The two large, subdued craters in the center of the mosaic are each about 1 kilometer (0.6 miles) wide. The boulder on the floor of the crater to the left is one of the larger rocks on Eros, more than 90 meters (295 feet) across. The whole scene is about 4 kilometers (2.5 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02933: Southwest of the Big Crater (Mosaic) sur le site de la NASA.

PIA03123: The Big Valley

NEAR Shoemaker's imager took this picture on November 18, 2000, from a vantage point 194 kilometers (120 miles) above the southern part of Eros' western hemisphere. The curvature of this part of Eros makes the asteroid look like a bent peanut. The scene is 6.8 kilometers (4.2 miles) across; the depth of field between the foreground (at right) and the horizon (at left) is nearly 30 kilometers (about 18 miles). While the imager was snapping this photo, the spacecraft's laser altimeter was measuring topography.

PIA02474: Eros' Eastern and Western Hemispheres

On February 23, 2000, the NEAR spacecraft obtained a sequence of image mosaics showing Eros' surface as the asteroid rotated under the spacecraft. At that time the range to the surface was approximately 355 kilometers (220 miles). These two mosaics, part of that sequence, show the stark beauty of the two opposite hemispheres. The smallest detail visible is 35 meters (120 feet) across. The top mosaic shows wavy brightness banding exposed in the interior walls of the saddle. In the bottom mosaic, similar banding is visible in one of the craters near the limb at left. To the right, the angle of the illumination accentuates the quasi-linear troughs near the terminator.

Successful firing of NEAR's thrusters yesterday, February 24, placed the spacecraft on course for insertion into the next lower orbit, at a 200 kilometer (120 mile) altitude. Images from that orbit, commencing in early March, will have nearly twice the spatial resolution of data returned so far.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02474: Eros' Eastern and Western Hemispheres sur le site de la NASA.

PIA02922: Eros' Latitude and Longitude Grid

The most familiar reference system for locating places on the surface of a planetary body is latitude and longitude. On a spherical body like Earth, these measures have a comfortable, predictable feel to them - despite the difficulty in showing a spherical planet on a flat map. However, the irregular peanut-like shape of Eros lends the asteroid's latitude-longitude grid a surprising character.

This image of the north polar region was taken from NEAR Shoemaker March 31, 2000, from an orbital altitude of 207 kilometers (129 miles). The image has been overlain with lines of latitude and longitude. Latitude is measured in degrees from the equator to the pole; longitude is measured in degrees west of a "prime meridian." In both cases, the vertex of the angle being measured is the center of Eros. The wandering, curved shapes of the lines are caused by the highly nonspherical and irregular asteroid shape.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02922: Eros' Latitude and Longitude Grid sur le site de la NASA.

PIA02925: Inside Eros' Large Crater

NEAR Shoemaker continues to take pictures of Eros under different lighting conditions and at better spatial resolution. This approach maximizes the amount of recognizable detail in the surface, while placing that detail into the context of the asteroid�s large-scale geography. This image approximates the view from the edge of the large, 5.3-kilometer (3.3-mile) diameter crater, looking into its depths. It was acquired on June 6, 2000, from an orbital altitude of 49 kilometers (30 miles). The whole scene is 1.4 kilometers (0.9 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02925: Inside Eros' Large Crater sur le site de la NASA.

PIA03124: An Unusual Perspective

NEAR Shoemaker captured this unusual view of the southwestern wall of Eros' saddle on November 24, 2000, from a 198-kilometer (123-mile) altitude. The camera is pointed west-southwest, looking down the length of the asteroid. The horizon is across the top of the picture. At lower left, the shadowed high terrain east of the saddle blocks the view of the illuminated western wall. The lowest part of the saddle, at the bottom center of the image, is barely illuminated. The dark areas at the very center of the picture and along the right side are in shadow.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03124: An Unusual Perspective sur le site de la NASA.

PIA02959: Vertigo

NEAR Shoemaker's images of Eros' horizon have provided us with breathtaking views of how different the skyline can be on another world. This picture, taken July 22, 2000, from an orbital altitude of 43 kilometers (27 miles), is a rare treat because it captures important information about Eros while playing with the viewer's senses. Here one of the asteroid's boulder fields decorates the skyline, but the orientation of the camera at the time the image was taken gives the illusion that the relatively gentle topography of the area really lies on a steep cliff. The whole scene is about 1.3 kilometers (0.8 miles) across.

PIA02957: A Lacework Surface

With the Sun high in Eros' sky, shadows disappear and bright surface features stand out. In this picture taken by NEAR Shoemaker on July 19, 2000, from an orbital altitude of 36 kilometers (22 miles), the Sun is nearly overhead. The steep local slopes are hard to see without shadows, but the lacework of bright and dark regolith is at its most conspicuous. The image shows a region about 800 meters (2,600 feet) across. The smallest visible rocks are about 6 meters (19 feet) across.

PIA02950: The Color of Regolith

On June 14, 2000, NEAR Shoemaker trained its camera on Eros' large, 5.3-kilometer (3.3-mile) diameter crater for a series of color pictures intended to measure the properties of regolith inside the asteroid's craters. In this false color view -- taken from an altitude of 50 kilometers (31 miles) -- redder hues represent rock and regolith that have been altered chemically by exposure to the solar wind and small impacts. Bluer hues represent fresher, less-altered rock and regolith, such as the bright patches that have been less affected by "space weathering." In that process, during micrometeorite impacts, rock reacts with miniscule amounts of trapped solar wind and is chemically changed. Interestingly, most of the large boulders have been just as affected as the regolith. This suggests either that the rocks are relatively old, or that they are "dirty" from an adhering film of regolith particles.

PIA03118: Eros at Closest Approach

This image was taken in the early hours of October 26, 2000, near the closest approach of NEAR Shoemaker's low-altitude flyover of Eros. At that time, the spacecraft's digital camera was looking at a region just 7 kilometers (4.3 miles) away, about 350 meters (1,150 feet) across. Most of the scene is covered in rocks of all sizes and shapes, but the floors of some craters are smooth, suggesting accumulation of fine regolith. For scale, the large boulder just below and to the right of the center of the picture is about 15 meters (50 feet) across. The smallest visible rocks are about 1.4 meters (5 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03118: Eros at Closest Approach sur le site de la NASA.

PIA02965: A Different World, Just Over the Hill

A fascinating finding from NEAR Shoemaker images is that even on a tiny world like Eros, geology can change just over the next hill. Such an abrupt change may not be surprising to someone driving from the Rocky Mountains to the western Plains, but it's a big surprise on an asteroid only 33 kilometers (21 miles) long. This NEAR Shoemaker picture, taken August 10, 2000, from an orbital altitude of 51 kilometers (32 miles), captured the view over an ancient, crater-battered hill into a valley where craters have been obliterated by resurfacing. The whole scene is only 1.6 kilometers (1 mile) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02965: A Different World, Just Over the Hill sur le site de la NASA.

PIA02499: Impact at High Noon

For people who live in mountain valleys, daylight can be a short-lived experience. Mountains to the east make the Sun rise later in the morning, while mountains to the west make the Sun set earlier in the evening. The brevity of daytime in a valley is accentuated during the shortened days of winter.

The floor of the 5.5-kilometer (3.4-mile) diameter impact crater that dominates one face of Eros experiences the ultimate in short daylight hours. Three factors conspire to make this true. Firstly, Eros rotates rapidly, once every 5.27 hours. Secondly, the crater's 0.9-kilometer (0.56-mile) high walls tend to block direct sunlight from the floor, even while the outside of the crater is illuminated. Thirdly, during the current season on Eros, the Sun never makes it high in the sky in this location.

This NEAR Shoemaker image, taken April 1, 2000, from a range of 209 kilometers (130 miles), caught the crater near local noon with the Sun highest in the sky. On that day, a hardy astronaut standing at the bottom of the crater would have experienced 1 hour and 45 minutes of daylight.

PIA02910: Over the Edge

Some of the most aesthetically pleasing views of Eros from NEAR Shoemaker have been obtained when the camera looks at the asteroid's horizon. This image was taken on May 15, 2000, from an orbital altitude of 52 kilometers (32 miles). The whole scene is about 1.4 kilometers (0.8 miles) across, and it shows features as small as 4 meters (13 feet) across. With the Sun high overhead, shadows are minimized and surface brightness variations stand out. Mottled brightness patterns as small as 30 meters (98 feet) across are evident near the horizon.

PIA03111: The Ups and Downs of Eros

While NEAR Shoemaker does not directly measure gravity on Eros' surface, the spacecraft gathers other data that allow scientists to infer this measurement. Radio tracking has been analyzed to determine the asteroid's gravitational "pull" on the orbiting spacecraft. The many images of the asteroid, plus range measurements from the laser altimeter, measure the body's shape. Comparisons of the shape with the gravitational pull felt by the spacecraft from different parts of its orbit show that the density of the interior must be nearly uniform.

The asteroid's shape, density and spin combine to create a bizarre pattern of what is "uphill" and "downhill." In this view, a map of "gravitational topography" has been painted onto a shape model. Red areas are "uphill" and blue areas are "downhill." A ball dropped onto one of the red spots would try to roll across the nearest green area to the nearest blue area.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03111: The Ups and Downs of Eros sur le site de la NASA.

PIA02497: Eros' Aging Craters

Eros' many craters have a range of ages dating back to the last time the asteroid's surface was "wiped clean" by geologic processes. This NEAR Shoemaker image of the tip of the asteroid, taken March 6, 2000, from a range of 201 kilometers (125 miles), shows craters with a variety of shapes and sizes. When small craters first form, they typically have sharp rims and round floors. As they age, progressively smaller craters are superimposed, rounding the rims and pitting the walls and floors until the original underlying crater becomes almost unrecognizable.

PIA03116: A Changing Picture of Eros

As NEAR Shoemaker has descended to lower orbits around Eros and returned higher spatial resolution pictures, knowledge of surface landforms has grown dramatically. The effect of changing spatial resolution can be illustrated by comparing these pictures of the large, 5.3-kilometer(3.3-mile) diameter crater taken at different distances above the surface. All of the views are shown with north to the top.

The upper left picture, taken February 12, 2000, from 1,682 kilometers(1,045 miles) above the crater, shows the feature's outline with several smaller craters superimposed on its southern section. There are only hints of bright materials on the north wall of the crater. The upper right view, taken April 2 from 193 kilometers (120 miles) above the crater, provides 8.7 times higher spatial resolution. The change in appearance is dramatic; details in the craters on the south rim are clearly visible and the patterns in brightness variation on the north wall are easily discerned. However, there are only the vaguest hints of boulders on the surface.

The picture at lower left was taken June 14 from 44 kilometers (27 miles) above the crater, and the picture at lower right was taken July 19 from 32 kilometers (20 miles) above the crater. These views provide 4.4 and 6times higher spatial resolution than in the view at upper right. Again, the increase in spatial resolution reveals a new level of detail. Boulders have become easily visible, as have fine, dark streaks pointed downslope within the bright material. Variations in brightness also appear at even smaller spatial scales than could be seen before.

When NEAR Shoemaker flies to within 5.3 kilometers (3 miles) of Eros' surface on October 26, spatial resolution will increase by another 4 to 6times compared to the two lower views shown here. A whole new level of detail in the shapes of rocks and patterns of brightness variation will be visible - and features not yet seen at all may be revealed.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03116: A Changing Picture of Eros sur le site de la NASA.

PIA02490: Eros' North Polar Region

On March 11, 2000, this image of Eros' north polar region was acquired by the imager on the NEAR Shoemaker spacecraft, from a range of 206 kilometers (127 miles). The area shown in the image is 10 kilometers (6.2 miles) across. Most of the north polar region is heavily cratered but the region to the left (part of the "saddle") has a lower crater density, indicating that the surface has been modified since it first formed. Eros' rotational axis lies nearly parallel to its orbital plane, much as with the planet Uranus, giving the asteroid exaggerated "seasons." Now, it is northern summer and the north pole is in continuous sunlight. The Sun will set there this June, at Eros' equivalent of Earth's autumnal equinox. At that time, Eros' south pole will begin 12 months of continuous illumination while the north pole remains in darkness.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02490: Eros' North Polar Region sur le site de la NASA.

PIA02926: A Swath of Eros

NEAR Shoemaker's scientific observations of Eros focus on different priorities as the spacecraft descends into lower orbits. For example, during the 100-kilometer (62-mile) orbit from April 11 - 22, 2000, the camera's mission was to build a global photomosaic under optimal viewing conditions. Due to the asteroid's irregular shape, doing this required imaging Eros repeatedly until each spot had been covered just right.

This swath of images - taken April 13 as part of that mapping campaign - shows several of the asteroid's major features. From top to bottom, these include large craters in the north polar region; part of the ridge that wraps one-third of the way around Eros; the western part of the saddle; and a dense field of enormous boulders.

PIA02470: Eros in color

This color image of Eros was acquired by NEAR's multispectral imager on February 12, 2000, at a range of 1100 miles (1800 kilometers). It is part of the final approach imaging sequence prior to orbit insertion and is intended to map the color properties of Eros across all of the illuminated surface. The image shows approximately the color that Eros would appear to the unaided human eye. Its subtle butterscotch hue is typical of a wide variety of minerals thought to be the major components of asteroids like Eros.

PIA03120: Color Mapping the Southern Hemisphere

NEAR Shoemaker took this image on October 30, 2000, from an orbital altitude of 189 kilometers (118 miles), as part of a color mapping sequence. The whole view is about 6.7 kilometers (4.2 miles) across and shows the inside of a 3.2-kilometer (2-mile) diameter crater. The brightness features on the crater's wall are characteristic of most of the larger craters on Eros.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03120: Color Mapping the Southern Hemisphere sur le site de la NASA.

PIA02921: Color View of the Saddle

Color imaging of Eros from the NEAR Shoemaker spacecraft has shown the asteroid's color variations are very subdued when compared to those of other planetary bodies, such as Mars. However, both the imager and the near-infrared spectrometer have detected discernible color differences between parts of the asteroid.

One location on Eros with distinctive color is the eastern side of the "saddle." This color composite image of that region was taken April 2, 2000, from an orbital altitude of 201 kilometers (125 miles). In this false color representation, the red and green image planes were taken in different wavelengths of infrared light, and the blue image plane was taken in blue light. NEAR scientists interpret the bright and greenish-gray appearing regions near the rim of the saddle to represent relatively fresh exposures of subsurface soil. In contrast, the pinkish looking soil covering other areas is thought to have been modified by exposure to small impacts and the solar wind.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02921: Color View of the Saddle sur le site de la NASA.

PIA02953: Common Craters (Earth and Eros)

The late Dr. Eugene Shoemaker, who many consider the founder of modern planetary science, did pioneering work at Meteor Crater, Arizona, documenting the effects of impact cratering as a planetary process. When part of a comet or asteroid strikes a planet or another asteroid, the resulting shock wave and excavation of rock and soil leave a characteristic landform that looks much the same from planet to planet, asteroid to asteroid. To illustrate the point, this NEAR Shoemaker image of a crater on Eros (left), taken July 6, 2000, from an orbital altitude of 50 kilometers (31 miles), is displayed next to and at approximately the same scale as Meteor Crater.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02953: Common Craters (Earth and Eros) sur le site de la NASA.

PIA02928: The Wall

This picture of Eros, taken from NEAR Shoemaker on June 20, 2000, shows a stunning aspect of the "bent" asteroid's peanut-like shape. The far side of the asteroid looms like an enormous wall beyond a near horizon in the foreground. The image was taken from an altitude of 51 kilometers (32 miles) and shows a region about 1.4 kilometers (0.9 miles) across.

PIA03129: Mysterious Surface Details

NEAR Shoemaker photographed this area of Eros on December 18, 2000, from an orbital altitude of 33 kilometers (21 miles). This part of the asteroid's surface, like many others, appears vaguely "sculptured" due to its low, elongated ridges and depressions with seemingly consistent orientations. Some of the low spots also contain accumulations of smooth, pond-like materials. Neither the surface sculpturing nor the pond-like materials are well understood, and both will be investigated in detail using even higher-resolution images from NEAR Shoemaker's low passes over Eros in early 2001. The whole scene is about 1 kilometer (0.6 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03129: Mysterious Surface Details sur le site de la NASA.

PIA02954: Shapes Galore

Exploration of small asteroids by spacecraft and ground-based radar has shown that these tiny worlds come in many sizes and shapes. This NEAR Shoemaker image, taken July 12, 2000, from an orbital altitude of 38 kilometers (24 miles), brings home the irregularity of the tiny little world called Eros. Looking down the length of the asteroid, one sees near, middle, and far horizons. The whole scene is about 0.9 kilometers (0.5 miles) across.

PIA02966: Sentinels

This NEAR Shoemaker picture, taken August 6, 2000, from an orbital altitude of 49 kilometers (30 miles), shows Eros' horizon near the time of local sunset. The surface is dark because of the oblique illumination, but several boulders catch the sunlight and appear like bright sentinels on the landscape. The brightest of the boulders, just to the upper right of the deeply shadowed crater in the foreground, is about 30 meters (100 feet) across. The whole scene is about 2.2 kilometers (1.4 miles) across.

PIA02493: Sunset on Eros

Eros' irregular shape gives rise to some stunning vistas at the time of sunrise or sunset. On March 6, 2000, the imager on the NEAR Shoemaker spacecraft caught this view of a stunning sunset. In the pitch black foreground the Sun has already set, but just over the horizon another part of the asteroid remains lit. Eros' rotation period is just 5 hours, 16 minutes, so in the course one 24-hour Earth day an observer on Eros would be treated to four full cycles of sunrises and sunsets.

PIA03115: Tracking a Feature on Eros

One of the strategies for characterizing the small-scale surface features on Eros is to photograph the same features under different lighting. Pictures taken with the Sun high in the sky show variations in the brightness of surface materials, while those taken when the Sun is low in the sky show morphology. Under a low Sun, the asteroid's rotation moves the direction of illumination, and linear features with different orientations are highlighted at different geometries.

A way to combine these measurements is in a "feature track," during which NEAR Shoemaker's camera is trained on a single site while the Sun moves through the sky. These four pictures were taken 18 minutes apart on October 7, 2000, during a feature track aimed at the inside of Eros' saddle region. The spacecraft was orbiting at an altitude of 103 kilometers (64 miles). Each frame is about 4.7 kilometers (2.9 miles) across. Variations in surface brightness are most conspicuous in the top two frames, whereas shallow grooves trending from the lower right to upper left are most easily seen in the bottom frames.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03115: Tracking a Feature on Eros sur le site de la NASA.

PIA02913: The Ridge at Sunrise

A particularly interesting landform on Eros is the long ridge that wraps around most of the asteroid's northern hemisphere. NEAR Shoemaker's digital camera captured part of that ridge just after local sunrise on May 20, 2000, from an orbital altitude of 50 kilometers (31 miles). The whole scene is about 1.4 kilometers (0.8 miles) across, and it shows features as small as 4 meters (13 feet). This part of the ridge is up to 250 meters (820 feet) wide, but both the width and the height of the feature vary along its length. The large number of superimposed craters indicates that the ridge is a relatively old feature.

PIA03112: A Road map for Eros

These four image mosaics of Eros illustrate the reference system the NEAR team uses to locate points on the asteroid's surface. Choosing from a variety of systems, the team members use latitude and longitude as their directional guide.

Latitude is the angle between the equatorial plane and a line connecting the surface point with the center of the body. By convention, the north pole is +90 degrees, the equator is 0 degrees, and the south pole is -90 degrees. Longitude is the angle around the rotational axis separating the point on the surface from the "prime meridian." The prime meridian selected by NEAR scientists is drawn though a large, bright crater at one end of Eros (indicated by an arrow in the lower left mosaic).

Again by convention, "west longitude" is used for most planetary bodies, including Eros, and it increases west from the prime meridian.

PIA02902: The Signs of the Times

NEAR Shoemaker's investigation of Eros from low altitude orbit continues to bring the asteroid's history into sharper focus. This pair of images, taken April 18, 2000, from an orbital height of 99 kilometers (61 miles), shows the dissimilarity of two different regions of the asteroid. The left panel shows a region typical of Eros, whereas the right panel shows the inside of the saddle. As the images show, the saddle region has far fewer craters.

Craters are formed by the explosive impacts of asteroid fragments that have rained onto the surface over the eons. A freshly exposed surface will have fewer craters than a surface exposed to space for a longer time. The lesser number of craters in the saddle shows that it has been wiped clean, or "resurfaced," by geologic processes relatively late in Eros' history.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02902: The Signs of the Times sur le site de la NASA.

PIA02485: Rim of Saddle Region on Eros

This image of the northeast rim of the saddle region on Eros was taken after NEAR entered into its 200 kilometer orbit on March 3, 2000. The resolution of this image is 20 meters (65 feet) per pixel. On the right are bright sinuous features associated with a ridge seen in previous images of the day. Parallel, closely spaced grooves are seen in the floor of the saddle. A cluster of boulders, ubiquitous on Eros, is seen in a small crater on the rim.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02485: Rim of Saddle Region on Eros sur le site de la NASA.

PIA02482: Interesting Structural Features on Eros

This image of the interior of Eros' saddle area, taken at a range of 204 km (127 miles), displays a paucity of craters compared to the surface on the right hand side of the image. The saddle displays many interesting structural features. Visible on the left wall are a series of closely spaced grooves that follow the terrain downslope. Opposite, on the upper right wall, trending towards the back of the saddle is a prominent ridge. Boulders are visible throughout this image. Features as small as 20 meters (65 feet) are discernable in this image.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02482: Interesting Structural Features on Eros sur le site de la NASA.

PIA02905: The View from Low Orbit

This image of Eros, taken from the NEAR Shoemaker spacecraft on May 1, 2000, is among the first to be returned from "low orbit." Between May and August, the spacecraft will orbit at altitudes near 50 kilometers (31 miles) or less. This will be the prime period of activity for some of the spacecraft's science instruments. The X-ray / gamma-ray spectrometer will build up maps of chemical abundances, while the laser rangefinder measures the shape of Eros to within meters (a few feet). At the same time the magnetometer will watch for indications of Eros' magnetic field and the near-infrared spectrometer will map rock types.

The imager will take pictures of the entire surface of Eros that capture features as small as 4 meters (13 feet) across. This particular image, taken from an orbital altitude of 53 kilometers (33 miles), shows a scene about 1.8 kilometers (1.1 miles) across. Numerous craters and boulders as small as 8 meters (26 feet) across dot the landscape. The large, rectangular boulder at the upper right is 45 meters (148 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02905: The View from Low Orbit sur le site de la NASA.

PIA03144: Landmarks at NEAR Shoemaker's Touchdown Site

This map projection of NEAR Shoemaker images shows locations and sizes of landmarks surrounding the spacecraft's planned landing site. Diameters of craters are shown in red, and diameters of boulders are shown in yellow. Diameters are given in units of meters (1 meter is about 3.3 feet). Coordinates along the left side of the map are degrees south latitude and coordinates along the bottom are degrees west longitude.

The six yellow "footprint" boxes represent approximate image size at 500,1,000, 1,500, 2,000, 2,500 and 3,000 meters above the surface during descent. The spacecraft will take pictures continuously between each spot. The arrow marks the estimated touchdown site.

Mosaic made from images taken January 25, 2001, from an altitude of about 25 kilometers (16 miles).

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03144: Landmarks at NEAR Shoemaker's Touchdown Site sur le site de la NASA.

PIA03138: Closing in on Eros

These four images are among thousands NEAR Shoemaker acquired during several low-altitude passes over Eros from January 25-28, 2001. From upper left to lower right, the images show Eros' bouldery surface at increasing resolution. The image at upper left was taken January 27 of a point 13.5 kilometers (8.4 miles) away; the one at the upper right was taken January 26 from 11.1 kilometers (6.9 miles) away. Each top scene is about 550 meters (1,815 feet) across. The image at bottom left was taken January 26 from 4.9 kilometers (3 miles) away, and the bottom right image was taken January 28 from a similar distance. Each lower scene is about 230 meters (760 feet) across.

PIA02468: Over Eros' Horizon

This incredible picture of Eros, taken on February 14, 2000, shows the view looking from one end of the asteroid across the gouge on its underside and toward the opposite end. In this mosaic, constructed from two images taken after the NEAR spacecraft was inserted into orbit, features as small as 120 feet (35 meters) across can be seen. House-sized boulders are present in several places; one lies on the edge of the giant crater separating the two ends of the asteroid. A bright patch is visible on the asteroid in the top left-hand part of this image, and shallow troughs can be see just below this patch. The troughs run parallel to the asteroid's long dimension.

PIA03143: Location of the NEAR Shoemaker Landing Site

The location of NEAR Shoemaker's planned landing site is shown in this image mosaic taken on December 3, 2000, from an orbital altitude of 200 kilometers (124 miles). In this view, south is to the top and the terminator (the imaginary line dividing day from night) lies near the equator. The landing site (at the tip of the arrow) is near the boundary of two distinctly different provinces, both of which the spacecraft will photograph as it descends. To the south and east (above and to the left) lies older, cratered terrain, while to the north (down) is the saddle-shaped feature Himeros, whose lesser density of superposed craters indicates relatively recent resurfacing by geologic processes.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03143: Location of the NEAR Shoemaker Landing Site sur le site de la NASA.

PIA02466: Eros details enhanced by computer processing

The NEAR camera's ability to show details of Eros's surface is limited by the spacecraft's distance from the asteroid. That is, the closer the spacecraft is to the surface, the more that details are visible. However mission scientists regularly use computer processing to squeeze an extra measure of information from returned data. In a technique known as "superresolution," many images of the same scene acquired at very, very slightly different camera pointing are carefully overlain and processed to bright out details even smaller than would normally be visible. In this rendition constructed out of 20 image frames acquired Feb. 12, 2000, the images have first been enhanced ("high-pass filtered") to accentuate small-scale details. Superresolution was then used to bring out features below the normal ability of the camera to resolve.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details.

Voir l'image PIA02466: Eros details enhanced by computer processing sur le site de la NASA.

PIA03131: Degraded Craters

NEAR Shoemaker captured this picture of two similarly sized craters in different states of preservation on January 1, 2001, from an orbital altitude of 35 kilometers (22 miles). The large "fresh" crater near the top of the frame exhibits a bowl shape with a relatively well-defined, sharp rim. The "degraded" one below it is puckered by smaller craters and probably partly buried by regolith, so the crisp detail visible in the top crater has been lost. The whole scene is about 0.9 kilometers (0.6 miles) across.

PIA02930: A Streaky Plain

Eros' "saddle," the large indentation in the asteroid's peanut-like shape, continues to reveal its diverse and fascinating landscapes. NEAR Shoemaker's camera snapped this picture of the southern part of the saddle on June 17, 2000, from an altitude of 51 kilometers (32 miles). Small craters are mostly absent, and on larger craters, the rims appear highly degraded and the floors flattened. These morphologic characteristics, when they appear on larger planets, typically are interpreted as evidence of blanketing on an older surface. On Eros, the blanketing layer would be regolith. The whole scene is approximately 1.9 kilometers (1.2 miles) across.

PIA02461: NEAR Approach to Eros

Approximately one day after its first rendezvous burn, NEAR imaged Eros every 15 degrees of rotation over a period of about 5.8 hrs. At this time the distance between the asteroid and spacecraft was approximately 4638 miles (7730 km). These images taken during approach to the asteroid are used by mission navigators and operators to make the proper corrections in the spacecraft's trajectory during the critical burns coming up on Feb. 8 and Feb. 14.

As an added bonus, these "OpNav" (optical navigation) images provide an increasingly detailed view of surface features on the asteroid. The resolution has increased to about 0.5 miles (0.8 km) per pixel, revealing the presence of 3 small craters on the surface. Over the next 10 days our view of the surface will become increasingly detailed and will allow for nearly global low resolution mapping of the asteroid before NEAR goes into orbit about Eros on Valentine's Day, Feb. 14. Once in orbit, NEAR's suite of scientific instruments will allow for global mapping of the asteroid at very high resolution.

PIA03136: Lowest Altitude Diversity

NEAR Shoemaker took this picture at 8:45 p.m. EST on January 25, 2001, during one of the spacecraft's low-altitude passes over the surface of Eros. The distance to the center of the picture is only 9 kilometers (5.6 miles), so the entire scene is a mere 340 meters (1,120 feet) across. At this scale, we can distinguish features less than 2 meters across. The asteroid's surface appears nearly devoid of obvious craters and is instead dominated by small boulders. In the upper left part of the image, a smooth deposit with a lower density of boulders is in contrast to the very rough-textured material seen at the lower right.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03136: Lowest Altitude Diversity sur le site de la NASA.

PIA02912: Pretty Sharp

Pictures taken during the low-orbit phase of NEAR Shoemaker's mission to Eros are revealing the true appearance of an asteroid's surface. Eros is turning out to have diverse surface types ranging from flat to hilly, smooth to rocky, and monotonously cratered to unique in character.

This picture was taken for "optical navigation," that is, plotting the spacecraft's course by tracking the positions of the landmarks below. It caught a spectacular view of a horizon sculpted by worn, degraded craters and punctuated by jagged boulders. The angular boulder at the center of the frame is about 60 meters (197 feet) tall, or two-thirds the length of a football field. Angular rocks are very common in nature; the corners form as a rock is chipped out of a larger mass.

This image was taken May 18, 2000, from an orbital altitude of 50 kilometers (31 miles). The whole scene is about 1.4 kilometers (0.8 miles) across, and it shows features as small as 4 meters (13 feet).

PIA02495: April Fool's Crater

Lighting and viewing geometries make a huge difference in the appearance of Eros' surface features. One of the most striking examples is the 2.7-kilometer (1.68-mile) diameter crater shown in these two images. The image at left, looking at the crater nearly edge-on, was taken February 16, 2000, from a range of 341 kilometers (212 miles). The image at right was taken high over the crater on March 2, 2000, from a range of 226 kilometers (140 miles). In the first image the only visible part of the crater's interior is the far, bright wall, which at the time was well-lit. The lighting, in combination with the particular viewing angle, make the crater appear stunningly bright. In the second view, the brighter material occupies only part of the slightly-shaded interior, greatly reducing the overall brightness contrast between the crater and the surrounding terrain.

PIA03113: The Shape of Eros

NEAR Shoemaker images provided the first model of Eros' shape, shown in this picture. An accurate model of Eros' shape helps the NEAR team determine the asteroid's key properties. The total space enclosed by the surface of the shape model represents the asteroid's estimated volume. The asteroid's mass (determined using NEAR Shoemaker's radio tracking) is divided by its volume to yield an estimate of its density - which is valuable for understanding what kind of rock makes up the interior. The shape also provides information about the distribution of mass below the surface, which scientists use to calculate surface gravity and thus the directions and steepness of slopes.

The positions of more than 2,000 landmarks on Eros were determined from more than 12,000 stereo measurements that generate a "grid" of points lying on the asteroid's surface. The shape model is a mathematical representation of the surface passing through all those points. The views at upper left, lower left and lower right show the shape model from over the equator (at 270 and 180 degrees west longitude) and the north pole (90north latitude), respectively. The shape model at upper right is overlain on an image acquired during approach to Eros.

PIA02492: Eros Color at Higher Resolution

As the NEAR Shoemaker spacecraft descends into lower orbits around Eros, it continually returns higher spatial resolution images of the asteroid. The true color image at left was taken February 12, 2000, from a range of 1,748 kilometers (1,083 miles), and shows details only as small as 180 meters (590 feet) across. It was taken two days before orbit insertion, as part of an image sequence designed to provide moderate-resolution color mapping of Eros at a near-constant viewing geometry. The true color image inset at right was taken February 29 from a range of 283 kilometers (175 miles) and shows much smaller details only 27 meters (89 feet) across. The higher spatial resolution (by a factor of six) brings out a whole class of surface details that were either invisible or at the margin of visibility in the earlier images. For example, the bright material on the wall of the large crater in the inset image is barely evident in the lower-resolution image at left, but by virtue of its limited spatial coverage the inset image lacks information on the crater's regional geologic setting. NEAR Shoemaker's imaging strategy makes use of both types of images, with lower-resolution images providing "context" for higher-resolution images that bring specific features into sharper focus.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02492: Eros Color at Higher Resolution sur le site de la NASA.

PIA03114: The South Saddle

NEAR Shoemaker's current 100-kilometer (62-mile) orbit gives it a bird's eye view of the asteroid. From this distance, only a handful of pictures are needed to create an image mosaic of a large area.

This mosaic of four frames, photographed on September 26, 2000, was taken as the spacecraft looked down on the "saddle" region from the south. The broad, curved depression that stretches vertically across the image is an area of the asteroid that was in shadow during the earlier 100-kilometer orbit, in April 2000. The area that appears speckled at the lower right is the same boulder-rich area featured as the April 4, 2000, Image-of-the-Day. The boulders are easily visible in the full-sized version of today's image.

PIA02967: Here's Looking at You

A large volume of images of Eros' surface have been taken in the nearly seven months that NEAR Shoemaker has been orbiting the asteroid. From these pictures, the first good understanding of the surface of an asteroid has begun to emerge. One of the key findings is a variety of brightness features inside Eros' craters. This picture, taken July 22, 2000, from an orbital altitude of 50 kilometers (31 miles), shows three craters, each about 600 meters (2000 feet) in diameter, aligned horizontally in this view across the bottom of the frame. The two craters at the right have well-developed, nearly continuous deposits of brightened regolith. In the crater at the left, more subtle, discrete tongues with elevated brightnesses are barely discernable on the crater wall. With a little imagination, the two craters to the right appear almost like eyeballs peering sideways at their distinctively different neighbor.

PIA02929: Down Slippery Slopes

Even the earliest, low-resolution images of Eros from NEAR Shoemaker show a variety of bright patches and bands on crater walls and other steep slopes. This picture, taken June 16, 2000, from an orbital altitude of 50 kilometers (31 miles), captures bright patches in two different environments. The crater in the top center of the picture has a bright patch on one of its walls, whereas the low, curved escarpment that snakes along the bottom of the image has bright material exposed along its length. The bright patches are a source of speculation, but they may have originated from exposure of subsurface material. The whole scene is approximately 1.9 kilometers (1.2 miles) across.

PIA03128: The Home Stretch Begins

NEAR Shoemaker obtained this image on December 15, 2000, from an altitude of 34 kilometers (21 miles), during the first days of its final low mapping orbit. The science strategy in this orbit focuses on very high-resolution imaging and measuring the elemental composition of the asteroid's surface using the X-ray and gamma-ray spectrometers. This picture, for example, covers a region only about 1.1 kilometers (0.7 miles) across, and each pixel projects onto the surface as a spot only about 2 meters (6 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03128: The Home Stretch Begins sur le site de la NASA.

PIA02955: The Shape of Eros

Looking at a few pictures of Eros under the right lighting conditions gives a reasonable idea of the shape of the asteroid, but analysis of NEAR Shoemaker data requires a very accurate digital model of Eros' shape. This "shape model" helps the NEAR team analyze images and other types of data. For example, comparing the brightness of imaged regions with the orientation of the corresponding parts of the surface, taken from the shape model, allows scientists to determine whether bright areas are due to just surface orientation or also to surface properties. By "filling

Voir l'image PIA02955: The Shape of Eros sur le site de la NASA.

PIA02952: The Battering and Debris

The many craters on Eros' surface attest to its battering by meteors - mostly debris ejected from other asteroids. This picture, taken July 7, 2000, from an orbital altitude of 50 kilometers (31 miles), neatly encapsulates the effects of a long history of impact cratering. Two overlapping craters, probably formed many millions of years apart, form a composite depression nearly 1.6 kilometers (1 mile) long. Large boulders, perhaps broken off Eros during these impacts, are perched on the craters' edge. The largest boulder, on the horizon in the center of the picture, is about 40 meters (130 feet) long. The whole scene is 1.8 kilometers (1.2 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02952: The Battering and Debris sur le site de la NASA.

PIA03121: A Look at Psyche

This view of the largest crater on Eros -- a mosaic of NEAR Shoemaker images taken Sept. 10, 2000, from an altitude of 62 miles (100 kilometers) - offers a new perspective on the feature known as Psyche. The images were taken as the spacecraft flew directly over the 3.3-mile (5.3 kilometer) wide crater and its smaller sister craters, which align its rim and create a paw-like appearance.

Providing additional clues to the history of Eros, the image shows several troughs and scarps that appear to cut through the crater. These structural features occurred after the crater was formed, perhaps resulting from a large impact elsewhere on the asteroid.

The low light coming from the right of the photo highlights the crater's raised rim. Bright patterns on the crater wall likely come from dark material moving downslope and revealing fresher material underneath. A large boulder perched on the crater wall illustrates Eros' unusual gravity; because of its elongated shape the gravity "lows" on Eros are not necessarily in the lowest parts of craters. In this section, the boulder seems to rest on the wall, instead of rolling down to the floor.

PIA02927: Peeking Into the Sunlight

NEAR Shoemaker images have shown many large boulders on Eros' surface, but seldom are the boulders as big and as close as the ones in this image taken on June 20, 2000, from an altitude of 51 kilometers (32 miles). Nestled within the 700-meter (2300-foot) diameter crater at the center of the picture are four particularly large rocks whose tops protrude out from the shadowed crater interior and into sunlight. The center boulder, the largest, is about 100 meters (330 feet) across. The whole scene is approximately 1.9 kilometers (1.2 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02927: Peeking Into the Sunlight sur le site de la NASA.

PIA03126: Multiple Horizons

NEAR Shoemaker took this picture looking across the saddle region of Eros on December 9, 2000, from an 80-kilometer (49-mile) altitude. The curvatures shown in the foreground and background are the eastern and western edges of the saddle, respectively. The high, bouldery area between is the broad ridge that separates the main eastern and western parts of the composite depression. The picture covers a region about 2.2 kilometers (1.4 miles) across.

PIA02471: Eros in stereo

Stereo imaging will be an important tool on NEAR for geologic analysis of Eros, because it provides three-dimensional information on the asteroid's landforms and structures. This anaglyph can be viewed using red-blue glasses to show Eros in stereo. It was constructed from images taken on February 14 and 15 that showed the same part of Eros from two slightly different viewing perspectives. The smallest feature visible is 100 feet (30 meters) across. For this image the spacecraft position was not optimum for stereo, but it will improve over the next few days allowing better 3-D views.

PIA03137: A Southern Hemisphere Overview

This mosaic of NEAR Shoemaker images, taken on December 3, 2000, from an orbital altitude of 200 kilometers (124 miles), provides an overview of the eastern part of the asteroid's southern hemisphere. In this view, south is to the top and the terminator (the imaginary line dividing day from night) lies near the equator. The conspicuous depression just above the center of the frame is the saddle-shaped feature Himeros.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03137: A Southern Hemisphere Overview sur le site de la NASA.

PIA02467: NEAR's first whole-Eros mosaic from orbit

This picture of Eros, the first of an asteroid taken from an orbiting spacecraft, is a mosaic of four images obtained by NEAR on February 14, 2000, immediately after the spacecraft's insertion into orbit. We are looking down over the north pole of Eros at one of the largest craters on the surface, which measures 4 miles (6 kilometers) across. Inside the crater walls are subtle variations in brightness that hint at some layering of the rock in which the crater formed. Narrow grooves that run parallel to the long axis of Eros cut through the southeastern part of the crater rim. A house-sized boulder is present near the floor of the crater; it appears to have rolled down the bowl-shaped crater wall. A large number of boulders is also present on other parts of the asteroid's surface. The surface of the asteroid is heavily cratered, indicating that Eros is relatively old.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02467: NEAR's first whole-Eros mosaic from orbit sur le site de la NASA.

PIA03130: Packed with Boulders

NEAR Shoemaker photographed the southern part of Eros' saddle region on December 19, 2000, from an orbital altitude of 37 kilometers (23 miles). The low ridge in the foreground (bottom) casts a wedge-shaped shadow against the hill in the background. The surface here is packed with boulders, the largest of which (near the center of the picture) is about 60 meters (200 feet) across. The whole scene is about 1.5 kilometers (0.9 miles) across.

PIA02931: Zebra Saddle

Within Eros' "saddle" - the large indentation in the peanut-shaped asteroid - diverse landscapes and brightness contrasts defy preconceived ideas of asteroids as mere cratered space rocks. NEAR Shoemaker took this image of the southwestern wall of the saddle on June 19, 2000, from an altitude of 51 kilometers (32 miles). The saddle wall contains bands of bright regolith, which may be exposed subsurface material yet to experience the "darkening" effects of surface impacts and solar wind. The whole scene is approximately 1.9 kilometers (1.2 miles) across.

PIA02469: Inside Eros' Giant Gouge

This picture was taken from NEAR on February 15, 2000, while the spacecraft was passing directly over the large gouge that creates Eros's characteristic peanut shape. It is a mosaic of individual images showing features as small as 120 feet (35 meters) across. Although most of the asteroid is in shadow, we are able to see inside the gouge. Many narrow parallel troughs closely follow the shape of the gouge. Although they appear curvilinear from this view, they are most likely oriented parallel to the length of the asteroid. The strong lighting contrast along the terminator (the line separating day from night on Eros) makes it easy to see that most of the surface is saturated with impact craters. Inside the gouge, however, only smaller craters are present, indicating that the area within the gouge is younger than the surface along the terminator. This implies that the event that caused the gouge must have happened more recently than the formation of the rest of the surface of Eros.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02469: Inside Eros' Giant Gouge sur le site de la NASA.

PIA03142: NEAR Shoemaker's Path

This plot shows NEAR Shoemaker's projected path from orbit to the surface of Eros on Feb. 12. Viewed from the sun, Eros is moving in a clockwise direction as it spins on its axis, while the spacecraft moves counterclockwise in a circular orbit 35 kilometers (22 miles) from the asteroid's center. The pair will be about 316 million kilometers (196 million miles) from Earth.

NEAR Shoemaker will de-orbit with a short engine burn at 10:31 a.m. EST, about 4 � hours before it's scheduled to reach the surface. The final leg of the controlled descent begins with the spacecraft about 5 kilometers (3 miles) above Eros; it will then execute an unprecedented series of four engine burns designed to slow its descent from about 20 mph to about 5 mph. NEAR Shoemaker is expected to touch down in an area bordering Himeros, the asteroid's distinctive saddle-shaped depression, after providing the highest-resolution images ever taken of Eros' boulder-strewn, cratered terrain.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03142: NEAR Shoemaker's Path sur le site de la NASA.

PIA03145: Final Eros Images: Range 1,150 meters (3,773 feet)

NEAR Shoemaker took this image of asteroid 433 Eros from a range of 1,150 meters (3,773 feet). The image is 54 meters (177 feet) across. The large rock at lower left is 7.4 meters (24 feet) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03145: Final Eros Images: Range 1,150 meters (3,773 feet) sur le site de la NASA.

PIA03139: The Subtle Colors of Eros

NEAR Shoemaker took these images of Eros on October 16, 2000, while orbiting 54 kilometers (34 miles) above the asteroid. They are shown in false color, constructed from images taken in green light and two different wavelengths of infrared light. Surface materials that have been darkened and reddened by the solar wind and micrometeorite impacts appear as pale brown, whereas fresher materials exposed from the subsurface on steep slopes appear in bright whites or blues. Compared with Gaspra and Ida, similar asteroids imaged in color from the Galileo spacecraft, Eros exhibits large brightness variations but only subtle color variations.

The top panorama shows the rounded rim of the saddle-shaped feature Himeros. The fresh, bright materials appear in localized patches set on a background of older fragmental debris, or regolith. In most regions of Eros, such as in the panorama and the view at lower left, the bright patches are strongly concentrated on the inner walls craters. However, on the inner wall of Himeros (lower right), steep slopes are extensive and the bright material appears as pervasive, scattered patches.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03139: The Subtle Colors of Eros sur le site de la NASA.

PIA02483: Cratered Terrain on Eros

This mosaic of 2 images, showing a cratered region of Eros located at the end of the elongated asteroid, was taken at a resolution of about 21 meters (69 feet) per pixel. A few of the craters show brightness (albedo) patterns on their walls, where the top portions of the walls are brighter than the surrounding terrain. The floors and lower portions of the walls of these craters have patches that appear darker than the surrounding terrain. A few boulders are also visible in this region. Some shallow, subdued troughs can also be seen trending vertically down the lower part of the asteroid.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02483: Cratered Terrain on Eros sur le site de la NASA.

PIA03105: Looking Along the Southern Hemisphere of Eros

The camera on NEAR Shoemaker caught this long view of Eros' southern hemisphere during a stereo imaging sequence on September 6, 2000, from an orbital altitude of 101 kilometers (63 miles). This view adds context to high-resolution images taken from lower orbits with "footprints" only one-fourth to one-third the size. Craters shown in the left foreground of the image are about 1.3 kilometers (0.8 miles) across.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA03105: Looking Along the Southern Hemisphere of Eros sur le site de la NASA.

PIA02904: Down, Down, Down

As the NEAR Shoemaker spacecraft continues its descent to lower orbits around Eros, smaller and smaller surface details are becoming visible. This image was taken April 29, 2000, from an orbital height of 84 kilometers (52 miles), just before the engine firing that placed NEAR in a 50-kilometer (31-mile) altitude orbit. The image shows features as small as 7 meters (23 feet) across and boulders a mere tens of meters in size. The whole scene is 3.2 kilometers (2 miles) across.

PIA02903: A Smorgasbord of Landforms

The images of Eros being returned by NEAR Shoemaker reveal a surprising diversity of interesting features. Many people's preconceptions of asteroids come from cinematic special effects that depict asteroids as little more than oversized tumbling rocks, perhaps tattered by strange, jagged landforms.

This image, taken April 17, 2000, from a distance of 101 kilometers (63 miles), suggests three words that could describe this asteroid: rocky, ridged, and rounded. The large boulder in the far left-center of the image measures more than 70 meters (230 feet) across. The ridge in the lower section of the frame is part of a feature that continues around a substantial part of the asteroid's middle. And although some of the small craters appear fresh and sharp, most of their rims have been rounded off by eons of relentless pounding by small, impacting meteors.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu/ for more details.

Voir l'image PIA02903: A Smorgasbord of Landforms sur le site de la NASA.

PIA02484: Oblique View of Eros' Crater

This image, showing an oblique view of Eros' large central crater, was taken at a resolution of about 20 meters (65 feet) per pixel. The brightness or albedo patterns on the walls of this crater are clearly visible, with the brighter materials near the tops of the walls and darker materials on the lower walls. Boulders are seen inside this crater and the smaller nearby craters. The higher density of craters to the left of the large crater implies that this region is older than the smoother area seen associated with the saddle region on the opposite side of the asteroid.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details.

Voir l'image PIA02484: Oblique View of Eros' Crater sur le site de la NASA.