The New Horizons Long Range Reconnaissance Imager (LORRI) snapped this photo of Jupiter's ring system on February 24, 2007, from a distance of 7.1 million kilometers (4.4 million miles).
This processed image shows a narrow ring, about 1,000 kilometers (600 miles) wide, with a fainter sheet of material inside it. The faint glow extending in from the ring is likely caused by fine dust that diffuses in toward Jupiter. This is the outer tip of the "halo," a cloud of dust that extends down to Jupiter's cloud tops. The dust will glow much brighter in pictures taken after New Horizons passes to the far side of Jupiter and looks back at the rings, which will then be sunlit from behind.
Jupiter's ring system was discovered in 1979, when astronomers spied it in a single image taken by the Voyager 1 spacecraft. Months later, Voyager 2 carried out more extensive imaging of the system. It has since been examined by NASA's Galileo and Cassini spacecraft, as well as by the Hubble Space Telescope and large ground-based observatories.
This mosaic of five images was taken through the clear filter (610 nanometers) of the solid state imaging system (CCD) aboard NASA's Galileo spacecraft on October 5, 1996. The mosaic is shown twice; the top panel displays only the data, while the bottom panel gives the location of some of Jupiter's small ring moons and presents a match between the image and a simple geometrical model of the gossamer rings. From the spacecraft's distance of approximately 6.6 million kilometers (km), the images have a resolution of about 134 km per pixel (picture element). The images were acquired when Galileo was in Jupiter's shadow, peering back toward the Sun, hidden behind the planet. The spacecraft was located only about 0.15 degrees above the ring plane at the time, making the images highly foreshortened in the vertical direction. North is to the bottom.
The white vertical arc at the left edge of the top panel is caused by sunlight filtering through Jupiter's upper atmosphere; the white horizontal line in the left part of the figure is the main ring whose arms overlap in this foreshortened view. The next frame of the mosaic, taken at higher sensitivity to detect fainter material, shows (on the left part of this panel) the overexposed main ring and the halo (seen as material above and below the main ring) which is interior to the main ring and has become visible in this longer exposure. The middle panel, taken at twenty times the standard sensitivity, shows a tenuous horizontal stripe, which can be made out in the "10 times sensitivity" panel also. In contrast to the main ring, which ends in a narrow elliptical tip, this "gossamer ring" ends abruptly (in the middle of the image) without changing its vertical thickness; the ring is also unusual in that its top and bottom edges are about twice as bright as the central region. Interestingly this ring is only seen to precisely the orbital distance of Amalthea, a small (mean radius of 85 km) Jovian moon, and has a half-thickness that is the same as Amalthea's maximum excursion off Jupiter's equatorial plane.
Satellite Interactions with Jupiter's Ring System
Further to the right, using much higher sensitivities, another faint but wider stripe becomes visible. This last band is associated with Thebe, a Jovian moon with a mean radius of 50 km. The ring lies principally inside Thebe's orbit and has a thickness like Thebe's elevation above Jupiter's equatorial plane. Given the position of Adrastea (in the equatorial plane at the periphery of the main Jovian ring), the main ring is likely derived from this small satellite (mean radius of 8 km).
The bottom rendition shows the orbital distances (in yellow) of the small satellites. The distances are given in units of Jovian radii; Jupiter's radius is 71,398 kilometers (44,267 miles). Various components of the Jovian ring system are plotted as seen from the equatorial plane: the green band represents the positions of particles lost from Amalthea; the red band is material from Thebe.
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo 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://solarsystem.nasa.gov/galileo/. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo.">http://www.jpl.nasa.gov/galileo/sepo.
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 Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo..
Voir l'image PIA00538: The Main Ring of Jupiter (clear filter) sur le site de la NASA.
The top and bottom panels show a mosaic of images of Jupiter's rings taken by NASA's Galileo spacecraft. Jupiter is to the right of this mosaic, and different brightness scales accent different parts of the ring system. Jupiter's ring system has three parts -- a flat main ring; a halo inside the main ring shaped like a double-convex lens; and the gossamer ring outside the main ring. In the top view, a faint mist of particles is seen above and below the main ring. This vertically extended "halo" is unusual in planetary rings, and is caused by electromagnetic forces pushing the smallest grains, which carry electric charges, out of the ring plane.
Development of Jupiter's Main Ring and Halo
Jupiter's main ring is a thin sheet of material encircling the planet. The near and far arms of this ring extend horizontally across the mosaic, joining together at the ring's ansa, the portion visible on the sides of Jupiter, on the figure's far left side. In the bottom view, some radial structure is visible across the ring's ansa. The diffuse innermost boundary begins at approximately 122,500 kilometers (about 76,100 miles). The main ring's outer radius is at about 128,940 kilometers (80,120 miles), very close to the orbit of the Jovian moon Adrastea (128,980 kilometers or 80,140 miles). The brightness of the main ring drops markedly at about 127,850 kilometers (79,440 miles), very near the orbit of another moon, Metis, at 127,978 kilometers (79,521 miles). Jupiter's four small satellites, Metis, Adrastea, Amalthea and Thebe, affect the structure of the huge planet's tenuous rings.
Jupiter's Main Ring and Halo
These images were taken through the clear filter of Galileo's onboard solid state imaging camera system on November 9, 1996. The resolution is approximately 24 kilometers (14 miles) per picture element along Jupiter's rings. Because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened vertically. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun, when the ring was approximately 2.3 million kilometers (1.4 million miles) away. The view of Earth's moon in the explanatory graphics was created from images returned by the Clementine lunar orbiter, launched in 1994 by NASA and the Ballistic Missile Defense Organization.
JPL manages the Galileo mission for NASA's Office of Space Science, Washington, DC.
The images are posted on the Internet at http://photojournal.jpl.nasa.gov/ and at http://galileo.jpl.nasa.gov.
Background information and educational context for the images can be found at: http://www.jpl.nasa.gov/galileo/sepo.
Voir l'image PIA01622: Jupiter's Main Ring and Halo sur le site de la NASA.
The schematic structures of Jupiter's main and gossamer rings are depicted here. Scientists studying data from NASA's Galileo spacecraft have found that the ring system is made up of impact debris created when meteoroids, which are fragments of comets and asteroids, slam into Jupiter`s four smallest satellites.
The top panel shows that the main ring (red) is formed mostly from meteoroid impact debris kicked up from the innermost moons, Metis (m) and Adrastea (a). Since both satellites orbit in paths not inclined to Jupiter's equator, the main ring appears as a narrow line.
The middle panel shows the additional effect of dust ejected from the satellite Amalthea (A), responsible for producing one of the two moon components of the gossamer ring. Amalthea's orbit is inclined to Jupiter's equatorial plane, and at different times the satellite's vertical position can range anywhere between the two extreme limits shown. Dust ejected from Amalthea (orange) produces a ring whose thickness equals Amalthea's vertical projections beyond Jupiter's equatorial plane.
Satellite Interactions with Jupiter's Ring System
The lower panel shows the additional effect of dust ejected from Thebe (T), which makes up the second component (shown in green) of the gossamer ring. Again, the two positions shown represent the maximum projections of Thebe from Jupiter's equatorial plane. This component of the gossamer ring is thicker than the component due to Amaltheas dust because Thebe's orbit is more inclined than that of Amalthea.
The Jupiter image was created from a map based on data obtained by the Hubble Space Telescope.
JPL manages the Galileo mission for NASA's Office of Space Science, Washington, DC.
The images are posted on the Internet at http://photojournal.jpl.nasa.gov/ and at http://solarsystem.nasa.gov/galileo/. Background information and educational context for the images can be found at: http://www.jpl.nasa.gov/galileo/sepo.">http://www.jpl.nasa.gov/galileo/sepo..
This mosaic of Jupiter's ring system was acquired by NASA's Galileo spacecraft when the Sun was behind the planet, and the spacecraft was in Jupiter's shadow peering back toward the Sun.
Galileo's November 1996 trajectory
In such a configuration, very small dust-sized particles are accentuated so both the ring particles and the smallest particles in the upper atmosphere of Jupiter are highlighted. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.
Jupiter's ring system is composed of three parts: a flat main ring, a toroidal halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. Only the main ring and a hint of the surrounding halo can be seen in this mosaic. In order to see the less dense components (the outer halo and gossamer ring) the images must be overexposed with respect to the main ring.
This composite of two mosaics was taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system on November 9, 1996, during Galileo's third orbit of Jupiter. The ring was approximately 2,300,000 kilometers away. The resolution is approximately 46 kilometers per picture element from right to left; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The vertical bright arcs in the middle of the ring mosaics show the edges of Jupiter and are composed of images obtained by NASA's Voyager spacecraft in 1979.
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo 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://solarsystem.nasa.gov/galileo/. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo.
Voir l'image PIA01621: Jupiter's Ring System sur le site de la NASA.
NASA's Galileo spacecraft acquired this mosaic of Jupiter's ring system (top) when the spacecraft was in Jupiter's shadow looking back toward the Sun. Jupiter's ring system (inset diagram) is composed of three parts: an outermost gossamer ring, a flat main ring, and an innermost donut-shaped halo. These rings are made up of dust-sized particles that are blasted off of the nearby inner satellites by small impacts. This image was taken on November 9, 1996 at a distance of 2.3 million kilometers (1.4 million miles).
Voir l'image PIA03001: Jovian Ring System Mosaic sur le site de la NASA.
Jupiter's ring system is composed of three parts - - a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, outside the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the figure's far left side. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa (top image). A faint mist of particles can be seen above and below the main rings. This vertically extended "halo" is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. To accentuate faint features in the bottom image of the ring halo, different brightnesses are shown through color. Brightest features are white or yellow and the faintest are purple.
Jupiter's main ring is a thin strand of material encircling the planet. The diffuse innermost boundary begins at approximately 123,000 kilometers (76,429 miles). The main ring's outer radius is found to be at 128,940 kilometers (80,119 miles) +/-50 kilometers (31 miles), slightly less than the Voyager value of 129,130 kilometers (80,237 miles) +/-100 kilometers (62 miles), but very close to the orbit of the satellite Adrastea (128,980 kilometers or 80,144 miles). The main ring exhibits a marked drop in brightness at 127,849 kilometers (79,441 miles) +/-50 kilometers (31 miles), lying almost atop the orbit of the Jovian moon Metis at 127,978 kilometers (79,521 miles). Satellites seem to affect the structure of even tenuous rings like those found at Jupiter.
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).
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. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo..
Voir l'image PIA00701: Jupiter's Main Ring/Ring Halo sur le site de la NASA.
Jupiter's ring system is composed of three parts: a flat main ring, a toroidal halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The gossamer ring is the extremely diffuse and uniform band that stretches across the center of this mosaic, starting from the main ring and halo on the right-hand side. The gossamer ring had been seen previously only in the single Voyager image in which it was discovered at a very low brightness level; there its brightness appeared to drop from about one-tenth the main ring's value until the ring totally vanished at a distance of about three Jovian radii. The gossamer ring is clearly visible in this Galileo view; the left side of the image corresponds to a radial distance of about 2.2 Jovian radii. The outer edge of the gossamer ring is beyond the edge of this mosaic.
Jupiter's gossamer ring
To accentuate the very faint, gossamer ring, the images were overexposed with respect to the main ring and the halo (both seen on the far right of the mosaic). In these long exposures, some stars are visible; other specks in the mosaic were caused by cosmic ray hits to the CCD. All parts of the Jovian rings scatter sunlight very efficiently in the forward direction, indicating that the particles are micrometers or less in diameter, small than the thickness of tissue paper. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.
These images were taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 9, 1996. The resolution is approximately 46 kilometers per picture element from right to left; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun; the ring was approximately 2.3 million kilometers (1.4 million miles) away. Jupiter lies about a full frame off the right edge.
The view of Earth's moon included in the explanatory graphics was created from imagery returned by the BMDO/NASA Clementine lunar orbiter which was launched in early 1994. (BMDO is Ballistic Missile Defense Organization.)
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo 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. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo.
Voir l'image PIA00659: Jupiter's Gossamer Ring sur le site de la NASA.
JPL manages the Voyager project for NASA's Office of Space Science.
Voir l'image PIA01529: Jupiter Ring System sur le site de la NASA.
Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa. A faint mist of particles can be seen above and below the main rings; this vertically extended "halo" is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic.
Jupiter's main ring is a thin strand of material encircling the planet. The diffuse innermost boundary begins at approximately 123,000 km. The main ring's outer radius is found to be at 128,940 +/-50 km, slightly less than the Voyager value of 129,130 +/-100 km, but very close to the orbit of the satellite Adrastea (128,980 km). The main ring exhibits a marked drop in brightness at 127,849 +/-50 km, lying almost atop the orbit of the Jovian moon Metis at 127,978 km. Satellites seem to affect the structure of even tenuous rings like that found at Jupiter.
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: http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.
Voir l'image PIA00657: Jupiter's Main Ring sur le site de la NASA.
This schematic cut-away view of the components of Jupiter's ring system shows the geometry of the rings in relation to Jupiter and to the small inner satellites, which are the source of the dust which forms the rings.
The Formation of Jupiter's Ring System
The innermost and thickest ring, shown in gray shading, is the halo that ends at the main ring. The thin, narrow main ring, shown with red shading, is bounded by the 16- kilometer-wide (10-miles) satellite Adrastea and shows a marked decrease in brightness near the orbit of Jupiter's innermost moon, Metis. It is composed of fine particles knocked off Adrastea and Metis. Although the orbits of Adrastea and Metis are about 1,000 kilometers (about 600 miles) apart, that separation is not depicted in this drawing. Impacts by small meteoroids (fragments of asteroids and comets) into these small, low-gravity satellites feed material into the rings. Thebe and Amalthea, the next two satellites in increasing distance from Jupiter, supply dust which forms the thicker, disk-like "gossamer" rings. The gossamer rings, depicted with yellow and green shading, are thicker because the source satellites orbit Jupiter on inclined paths
Satellite Interactions with Jupiter's Ring System
These small satellites all orbit closer to Jupiter than the four largest Galilean satellites, Io, Europa, Ganymede and Callisto, which were discovered nearly 400 years ago. The orbital distances of the moons are drawn relative to the size of Jupiter.
Jupiter's Main Ring and Inner SatellitesSide view of system:Overhead view of system:The Jupiter image was created from a map based on data obtained by the Hubble Space Telescope.
JPL manages the Galileo mission for NASA's Office of Space Science, Washington, DC. The images are posted on the Internet at http://photojournal.jpl.nasa.gov/ and at http://solarsystem.nasa.gov/galileo/. Background information and educational context for the images can be found at: http://www.jpl.nasa.gov/galileo/sepo.">http://www.jpl.nasa.gov/galileo/sepo..
Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.
A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal "halo" is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest being white or yellow and the faintest purple.
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: http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.
Voir l'image PIA00658: Jupiter's Ring Halo sur le site de la NASA.
