This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S./French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Nov. 10, 1997. The volume of extra warm surface water (shown in white) in the core of the El Niņo continues to increase, especially in the area between 15 degrees south latitude and 15 degrees north latitude in the eastern Pacific Ocean. The area of low sea level (shown in purple) has decreased somewhat from late October. The white and red areas indicate unusual patterns of heat storage; in the white areas, the sea surface is between 14 centimeters and 32 cm (6 inches to 13 inches) above normal; in the red areas, it is about 10 centimeters (4 inches) above normal. The surface area covered by the warm water mass is about one-and-one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21 to 30 degrees Celsius (70 to 85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level.
The El Niņo phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white areas) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmospheric system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration (NOAA) has issued an advisory indicating the presence of a strong El Niņo condition throughout the winter.
For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/
Voir l'image PIA01085: TOPEX/El Niņo Watch - Warm Water Pool is Increasing, Nov. 10, 1997 sur le site de la NASA.
Global images of Earth from Galileo. In each frame, the continent of Antarctica is visible at the bottom of the globe. South America may be seen in the first frame (top left), the great Pacific Ocean in the second (bottom left), India at the top and Australia to the right in the third (top right), and Africa in the fourth (bottom right). Taken at six-hour intervals on December 11, 1990, at a range of between 2 and 2.7 million kilometers (1.2 to 1.7 million miles). P-37630
These images were taken during Galileo's first Earth flyby. This gravity assist increased Galileo's speed around the Sun by about 5.2 kilometers per second (or 11,600 miles per hour) and substantially redirected Galileo as required for its flybys of the asteroid Gaspra in October 1991 and Earth in 1992. Galileo's closest approach (960 kilometers, or 597 miles, above the Earth's surface) to the Earth was on December 8, 1990, 3 days before these pictures were taken.
Each of these images is a color composite, made up using images taken through red, green, and violet filters. The four images are part of the Galileo Earth spin movie, a 256-frame time-lapse motion picture that shows a 25-hour period of Earth's rotation and atmospheric dynamics. The movie gives scientists a unique overall view of global weather patterns, as opposed to the limited view of weather satellite images.
The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.
Voir l'image PIA00728: Global Images of Earth sur le site de la NASA.
The distribution of ocean surface winds over the Atlantic Ocean, based on September 1999 data from NASA's SeaWinds instrument on the QuikScat satellite, shows wind direction (white streamlines) at a resolution of 25 kilometers (15.5 miles), superimposed on the color image indicating wind speed.
Over the ocean, the strong (seen in violet) trade winds blow steadily from the cooler subtropical oceans to warm waters just north of the equator. The air rises over these warm waters and sinks in the subtropics at the horse latitudes. Low wind speeds are indicated in blue. In the mid-latitudes, the high vorticity caused by the rotation of the Earth generates the spirals of weather systems. The North Atlantic is dominated by a high-pressure system, whose anti-cyclonic (clockwise) flow creates strong winds blowing parallel to the coast of Spain and Morocco. This creates strong ocean upwelling and cold temperature. Hurricane Floyd, with its high winds (yellow), is clearly visible west of the Bahamas. Tropical depression Gert is seen as it was forming in the tropical mid-Atlantic (as an anti-clockwise spiral); it later developed into a full-blown hurricane.
Because the atmosphere is largely transparent to microwaves, SeaWinds is able to cover 93 percent of the global oceans, under both clear and cloudy conditions, in a single day, with the capability of a synoptic view of the ocean. The high resolution of the data also gives detailed description of small and intense weather systems, like Hurricane Floyd. The image in the insert is based on data specially produced at 12.5 kilometers (7.7 miles). In the insert, white arrows of wind vector are imposed on the color image of wind speed. The insert represents a 3-degree area occupied by Hurricane Floyd. After these data were acquired, Hurricane Floyd turned north. Its strength and proximity to the Atlantic coast of the U.S. caused the largest evacuation of citizens in U.S. history. Its landfall on September 16, 1999 resulted in severe flooding and devastation in the Carolinas. The high-resolution SeaWinds data provided an opportunity to monitor and study this hurricane.
NASA's Earth Science Enterprise is a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system. JPL is a division of the California Institute of Technology, Pasadena, CA.
Voir l'image PIA02455: SeaWinds Global Coverage with Detail of Hurricane Floyd sur le site de la NASA.
On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990.
Voir l'image PIA00134: Earth - Moon Conjunction sur le site de la NASA.
MGS MOC Release No. MOC2-368, 22 May 2003
Globe diagram illustrates the Earth's orientation as viewed from Mars (North and South America were in view).
Earth/Moon: This is the first image of Earth ever taken from another planet that actually shows our home as a planetary disk. Because Earth and the Moon are closer to the Sun than Mars, they exhibit phases, just as the Moon, Venus, and Mercury do when viewed from Earth. As seen from Mars by MGS on 8 May 2003 at 13:00 GMT (6:00 AM PDT), Earth and the Moon appeared in the evening sky. The MOC Earth/Moon image has been specially processed to allow both Earth (with an apparent magnitude of -2.5) and the much darker Moon (with an apparent magnitude of +0.9) to be visible together. The bright area at the top of the image of Earth is cloud cover over central and eastern North America. Below that, a darker area includes Central America and the Gulf of Mexico. The bright feature near the center-right of the crescent Earth consists of clouds over northern South America. The image also shows the Earth-facing hemisphere of the Moon, since the Moon was on the far side of Earth as viewed from Mars. The slightly lighter tone of the lower portion of the image of the Moon results from the large and conspicuous ray system associated with the crater Tycho.
A note about the coloring process: The MGS MOC high resolution camera only takes grayscale (black-and-white) images. To "colorize" the image, a Mariner 10 Earth/Moon image taken in 1973 was used to color the MOC Earth and Moon picture. The procedure used was as follows: the Mariner 10 image was converted from 24-bit color to 8-bit color using a JPEG to GIF conversion program. The 8-bit color image was converted to 8-bit grayscale and an associated lookup table mapping each gray value of the image to a red-green-blue color triplet (RGB). Each color triplet was root-sum-squared (RSS), and sorted in increasing RSS value. These sorted lists were brightness-to-color maps for the images. Each brightness-to-color map was then used to convert the 8-bit grayscale MOC image to an 8-bit color image. This 8-bit color image was then converted to a 24-bit color image. The color image was edited to return the background to black.
Voir l'image PIA04531: Earth and Moon as viewed from Mars sur le site de la NASA.
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MESSENGER's Earth flyby on Aug. 2, 2005, not only adjusted the spacecraft's path to Mercury - the gravity assist maneuver allowed the spacecraft team to test several MESSENGER science instruments by observing its home planet.
The Mercury Dual Imaging System's wide-angle camera passed with flying colors—several of them, actually—snapping a number of images across its full multispectral capability. The camera is designed to characterize minerals that may have formed in Mercury's crust. Telescope measurements from Earth suggest that Mercury's surface resembles the highlands on our moon: abundant feldspar (anorthite) with limited amounts of iron-rich minerals such as pyroxene and olivine. The MESSENGER team carefully picked 11 filters across visible and near-infrared wavelengths (400 to 1,100 nanometers) known to indicate these and other common silicate minerals.
This side-by-side look at Earth illustrates the value of multiple-wavelength imaging. The three-band composite at left is made from filters with peak sensitivities near 480 nm, 560 nm and 630 nm. These filters help distinguish materials with distinct visible color differences (ilmenite, volcanic glasses) but are also very close to the sensitivity of the human eye. (Natural color is somewhat subjective, so this combination of bands is "approximate" natural color.) The spacecraft was 63,950 miles (102,918 kilometers) above Earth when the images were taken.
The camera's computer can mix red, green, and blue (RGB) light in various proportions to create a full spectrum of colors. Infrared images are visualized by substituting one of the RGB components. On the right, the red component is the 750 nm band and green and blue are formed from the 630 nm and the 560 nm bands. Despite the substitution of only one band, the results are dramatically different. Continental areas are mostly red due to the high reflectance of vegetation in the near-infrared. Short wavelength light (blue) is easily scattered in the Earth's atmosphere, producing our blue skies, but also obscuring the surface from MESSENGER's viewpoint. Infrared light is not easily scattered, so images of the Earth remain sharp. The red coloring in the center of the image is a reflection of the Brazilian rain forests and other vegetation in South America.
Once in orbit around Mercury, MESSENGER will map the entire surface in all eleven wavelengths—and at resolutions ten times better than seen in this view of Earth.
These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.
Voir l'image PIA10122: Twins Image sur le site de la NASA.
Photo Credit: Image produced by F. Hasler, M. Jentoft-Nilsen, H. Pierce, K. Palaniappan, and M. Manyin. NASA Goddard Lab for Atmospheres - Data from National Oceanic and Atmospheric Administration (NOAA).
Voir l'image PIA01462: The Americas and Hurricane Andrew sur le site de la NASA.
This view of the Earth shows a wonderfully unique but physically impossible view of the southern hemisphere and Antarctica. While a spacecraft could find itself directly over the Earth's pole, roughly half of the image should be in darkness! This view was created by mosaicing together several images taken by Galileo over a 24 hour period and projecting them as they would be seen from above the pole. The continents of South America, Africa, and Australia are respectively seen at the middle left, upper right, and lower right. The slightly bluish ice and snow of Antarctica include large ice shelves (upper left, lower middle), a broad fan of broken offshore pack ice (lower left and middle) and continental glaciers protruding into the sea (lower right). The regularly spaced weather systems are prominent.
Most spacecraft traveling near the Earth's poles are in very low Earth orbit, and cannot acquire panoramic shots like this one. Galileo's view of the southern hemisphere, combined with the spacecraft's special spectral properties (four separate narrowband filters that measure the brightness of reflected light at specific infrared wavelengths), led to a number of unique observations. For example, Galileo's cameras distinguished between ice and high stratospheric clouds, allowing scientists to study the correlation between these clouds and growth of the ozone hole.
The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.
Voir l'image PIA00729: South Polar Projection of Earth sur le site de la NASA.
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This sequence of three images, obtained by NASA's Cassini spacecraft over the course of about 10 minutes, shows the path of a newly found moonlet in a bright arc of Saturn's faint G ring.
In each image, a small streak of light within the ring is visible. Unlike the streaks in the background, which are distant stars smeared by the camera's long exposure time of 46 seconds, this streak is aligned with the G ring and moves along the ring as expected for an object embedded in the ring.
Cassini scientists interpret the moving streak to be reflected light from a tiny moon half a kilometer (a third of mile) wide that is likely a major source of material in the arc and the rest of the G ring. Debris knocked off this moon forms a relatively bright arc of material near the inner edge of the G ring, the most visible part of the ring in these images. That arc, in turn, leaks material to form the entire ring.
These images were captured by Cassini's narrow-angle camera on Oct. 27, 2008. The first image (left) was taken in visible light, the second image (middle) was taken in red light, and the third image (right) in near-infrared light centered at a wavelength of 750 nanometers. Image scale for the first image is 7 kilometers (4 miles) per pixel. The second and third images were taken at reduced resolution. These spatially compressed images were captured at 14 kilometers (9 miles) per pixel and then displayed at a size equal to the first image. This view looks toward the un-illuminated side of the rings from about 5 degrees above the ringplane. The view was acquired at a distance of approximately 1.2 million kilometers (751,000 miles) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 23 degrees.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The Cassini imaging team homepage is at http://ciclops.org.
Voir l'image PIA11148: Tiny Moonlet Within G Ring Arc sur le site de la NASA.
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system.
In figure 1, Earth is captured in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare.
The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees.
A magnified view of this image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across.
Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See PIA08321, for a more detailed view of these newly-revealed features.
The narrow tenuous G ring and the main rings are seen at the right.
The view looks down from about 15 degrees above the un-illuminated side of the rings.
Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is 129 kilometers (80 miles) per pixel.
At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm. The Cassini imaging team homepage is at http://ciclops.org.
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Galapagos Islands Image
The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005. One picture, snapped when MESSENGER was 34,692 miles (55,831 kilometers) above Earth, shows the Galapagos Islands as tiny specks peeking through an opening in clouds of the brightly lit dayside of the planet. The line dividing day and night cuts a swath through South America, with night about to fall on the western half of the continent. The large bright spot to the west of South America is the Sun's light scattering off ocean waves.
These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.
Voir l'image PIA10121: Galapagos Islands Image sur le site de la NASA.
The High Resolution Imaging Science Experiment (HiRISE) camera would make a great backyard telescope for viewing Mars, and we can also use it at Mars to view other planets. This is an image of Earth and the moon, acquired on October 3, 2007, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter.
At the time the image was taken, Earth was 142 million kilometers (88 million miles) from Mars, giving the HiRISE image a scale of 142 kilometers (88 miles) per pixel, an Earth diameter of about 90 pixels and a moon diameter of 24 pixels. The phase angle is 98 degrees, which means that less than half of the disk of the Earth and the disk of the moon have direct illumination. We could image Earth and moon at full disk illumination only when they are on the opposite side of the sun from Mars, but then the range would be much greater and the image would show less detail.
On the day this image was taken, the Japanese Kayuga (Selene) spacecraft was en route from the Earth to the moon, and has since returned spectacular images and movies (see http://www.jaxa.jp/projects/sat/selene/index_e.html).
On the Earth image we can make out the west coast outline of South America at lower right, although the clouds are the dominant features. These clouds are so bright, compared with the moon, that they are saturated in the HiRISE images. In fact the red-filter image was almost completely saturated, the Blue-Green image had significant saturation, and the brightest clouds were saturated in the infrared image. This color image required a fair amount of processing to make a nice-looking release. The moon image is unsaturated but brightened relative to Earth for this composite. The lunar images are useful for calibration of the camera.
NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.
Voir l'image PIA10244: Earth and Moon as Seen from Mars sur le site de la NASA.
This image was taken on June 26, 2007, UTC 20:00. In this image an obvious storm hangs over the middle of the United States. Figure 1 shows CloudSat data looking, in profile, at the cloud in this storm. The vertical axis represents the altitude from the ground to the top of the atmosphere. The variations of color intensity are differences in reflectivity and an indication of the differing amounts of water and ice in the storm clouds. The bright line at the bottom of the panel is the ground return from the radar. This indicates that the radar penetrated to the ground most of the time, even through heavy rainfall. Where the ground return disappears is an indication that the radar was attenuated by heavy precipitation, likely exceeding 30 mm/hr, based on previous studies. From one side to the other, the bottom panel is approximately 800 km, and the vertical scale from top to bottom is approximately 30 km. The CloudSat data provide analysts and forecasters with a view of storms never before available. Cross-sections like these provide a view of the internal structure of these storms, giving information about the intensity, rainfall rates, and cloud organization.
Quicklook Images can viewed at the CloudSat Data Processing Center.
Mariner 10 was launched on November 3, 1973, 12:45 am PST, from Cape Canaveral on an Atlas/Centaur rocket (a reconditioned Intercontinental Ballistic Missile - ICBM). Within 12 hours of launch the twin cameras were turned on and several hundred pictures of both the Earth and the Moon were acquired over the following days.
The Earth and Moon were imaged by Mariner 10 from 2.6 million km while completing the first ever Earth-Moon encounter by a spacecraft capable of returning high resolution digital color image data. These images have been combined at right to illustrate the relative sizes of the two bodies. From this particular viewpoint the Earth appears to be a water planet!
The Mariner 10 mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.
Voir l'image PIA02441: Earth and Moon as viewed by Mariner 10 sur le site de la NASA.
The SeaWinds scatterometer on the QuikScat satellite makes global radar measurements -- day and night, in clear sky and through clouds. The radar data over the oceans provide scientists and weather forecasters with information on surface wind speed and direction. Scientists also use the radar measurements directly to learn about changes in vegetation and ice extent over land and polar regions.
This false-color image is based entirely on SeaWinds measurements obtained over oceans, land, and polar regions. Over the ocean, colors indicate wind speed with orange as the fastest wind speeds and blue as the slowest. White streamlines indicate the wind direction. The ocean winds in this image were measured by SeaWinds on September 20, 1999. The large storm in the Atlantic off the coast of Florida is Hurricane Gert. Tropical storm Harvey is evident as a high wind region in the Gulf of Mexico, while farther west in the Pacific is tropical storm Hilary. An extensive storm is also present in the South Atlantic Ocean near Antarctica.
The land image was made from four days of SeaWinds data with the aid of a resolution enhancement algorithm developed by Dr. David Long at Brigham Young University. The lightest green areas correspond to the highest radar backscatter. Note the bright Amazon and Congo rainforests compared to the dark Sahara desert. The Amazon River is visible as a dark line running horizontally though the bright South American rain forest. Cities appear as bright spots on the images, especially in the U.S. and Europe.
The image of Greenland and the north polar ice cap was generated from data acquired by SeaWinds on a single day. In the polar region portion of the image, white corresponds to the largest radar return, while purple is the lowest. The variations in color in Greenland and the polar ice cap reveal information about the ice and snow conditions present.
NASA's Earth Science Enterprise is a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system. JPL is a division of the California Institute of Technology, Pasadena, CA.
Voir l'image PIA02458: SeaWinds - Oceans, Land, Polar Regions sur le site de la NASA.
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The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of its home planet on Aug. 2, 2005. Several hundred images, taken with the wide-angle camera in MESSENGER's Mercury Dual Imaging System (MDIS), were sequenced into a movie documenting the view from MESSENGER as it departed Earth.
Comprising 358 frames taken over 24 hours, the movie follows Earth through one complete rotation. The spacecraft was 40,761 miles (65,598 kilometers) above South America when the camera started rolling on Aug. 2. It was 270,847 miles (435,885 kilometers) away from Earth—farther than the Moon's orbit—when it snapped the last image on Aug. 3.
These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.
Voir l'image PIA10120: Earth Departure Movie sur le site de la NASA.
This global digital map of Saturn's moon Titan was created using images taken by the Cassini spacecraft's imaging science subsystem.
The images were taken using a filter centered at 938 nanometers, allowing researchers to examine variations in albedo (or inherent brightness) across the surface of Titan. Because of the scattering of light by Titan's dense atmosphere, no topographic shading is visible in these images.
The map is an equidistant projection and has a scale of 4 kilometers (2.5 miles) per pixel. Actual resolution varies greatly across the map, with the best coverage (close to the map scale) near the center and edges of the map and the worst coverage on the leading hemisphere (centered around 120 degrees west longitude).
Imaging coverage in the northern polar region continues to improve as Titan approaches northern vernal equinox in August 2009 and the north pole comes out of shadow. Large dark areas, strongly suspected to be liquid-hydrocarbon-filled lakes, have been documented at high latitudes (see PIA11146).
The mean radius of Titan used for projection of this map is 2,575 kilometers (1,600 miles). Until a control network is created for Titan, the satellite is assumed to be spherical.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The Cassini imaging team homepage is at http://ciclops.org.
Voir l'image PIA11149: Map of Titan - February 2009 sur le site de la NASA.
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