Galerie de photos de Phobos, satellite de la planète Mars

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<h1>PIA00078: Gaspra, Deimos, and Phobos Comparison</h1><div class="PIA00078" lang="en" style="width:293px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This montage shows asteroid 951 Gaspra (top) compared with Deimos (lower left) and Phobos (lower right), the moons of Mars. The three bodies are shown at the same scale and nearly the same lighting conditions. Gaspra is about 17 kilometers (10 miles) long. All three bodies have irregular shapes, due to past catastrophic conditions. However their surfaces appear remarkably different, possibly because of differences in composition but most likely because of very different impact histories. The Phobos and Deimos images were obtained by the Viking Orbiter spacecraft in 1977; the Gaspra image is the best of a series obtained by the Galileo spacecraft on October 29, 1991. Galileo is scheduled to add the detailed view of another asteroid when it flies by Ida in August 1993. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00078" onclick="window.open(this.href); return false;" title="Voir l'image PIA00078: Gaspra, Deimos, and Phobos Comparison sur le site de la NASA">Voir l'image PIA00078: Gaspra, Deimos, and Phobos Comparison sur le site de la NASA.</a></div>
PIA00078: Gaspra, Deimos, and Phobos Comparison
<h1>PIA01332: MOC Image of Phobos with TES Temperature Overlay</h1><div class="PIA01332" lang="en" style="width:462px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. The Thermal Emission Spectrometer (TES) measured the brightness of thermal radiation at the same time the camera acquired this image. By analyzing the brightness, TES scientists could deduce the various fractions of the surface exposed to the Sun and their temperatures. This preliminary analysis shows that the surface temperature, dependent on slope and particle size, varies from a high of +25° F (-4° C) on the most illuminated slopes to -170° F (-112° C) in shadows. This large difference, and the fact that such differences can be found in close proximity, adds support to the notion that the surface of Phobos is covered by very small particles.<p>Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01332" onclick="window.open(this.href); return false;" title="Voir l'image PIA01332: MOC Image of Phobos with TES Temperature Overlay sur le site de la NASA">Voir l'image PIA01332: MOC Image of Phobos with TES Temperature Overlay sur le site de la NASA.</a></div>
PIA01332: MOC Image of Phobos with TES Temperature Overlay
<h1>PIA01333: High-Resolution MOC Image of Phobos</h1><div class="PIA01333" lang="en" style="width:683px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image shows a close-up of the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater, and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite.<p>Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01333" onclick="window.open(this.href); return false;" title="Voir l'image PIA01333: High-Resolution MOC Image of Phobos sur le site de la NASA">Voir l'image PIA01333: High-Resolution MOC Image of Phobos sur le site de la NASA.</a></div>
PIA01333: High-Resolution MOC Image of Phobos
<h1>PIA01334: High-Resolution MOC Image of Phobos with Graphics Overlay</h1><div class="PIA01334" lang="en" style="width:273px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. The white boxes indicate the location of the subframes or close-ups: that on the left is C and that on the right is D. Each box is 1.92 kilometers (1.19 miles) square. The image shows several new features of this lumpy moon -- features that are associated with the prominent crater seen in the upper left quarter of the image. This is the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater (D), and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. The far wall of the crater shows lighter and darker streaks going down the slopes (C). Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite.<p>Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01334" onclick="window.open(this.href); return false;" title="Voir l'image PIA01334: High-Resolution MOC Image of Phobos with Graphics Overlay sur le site de la NASA">Voir l'image PIA01334: High-Resolution MOC Image of Phobos with Graphics Overlay sur le site de la NASA.</a></div>
PIA01334: High-Resolution MOC Image of Phobos with Graphics Overlay
<h1>PIA01335: High-Resolution MOC Image of Phobos' Stickney Crater</h1><div class="PIA01335" lang="en" style="width:480px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image is a close-up of the far wall of the Stickney crater, 10 kilometers (6 miles) in diameter, that is the largest crater on Phobos. This image shows lighter and darker streaks going down the slopes (C). The presence of material of different brightness on the far crater slopes and in some of the grooves shows that the satellite is heterogeneous (that is, it is made of a mixture of different types of materials). The motion of debris down slopes is guided by gravity, which is only about 1/1000th that of the Earth -- e.g., a 68-kilogram (150-pound) person would weigh only about 57 grams (2 ounces) on Phobos. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite.<p>Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01335" onclick="window.open(this.href); return false;" title="Voir l'image PIA01335: High-Resolution MOC Image of Phobos' Stickney Crater sur le site de la NASA">Voir l'image PIA01335: High-Resolution MOC Image of Phobos' Stickney Crater sur le site de la NASA.</a></div>
PIA01335: High-Resolution MOC Image of Phobos' Stickney Crater
<h1>PIA01336: High-Resolution MOC Image of Phobos' Face</h1><div class="PIA01336" lang="en" style="width:480px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. The minimum distance between the spacecraft and Phobos was 1,080 kilometers (671 miles). Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite. The image shows several new features of this lumpy moon -- features that are associated with the prominent crater seen in the upper left quarter of the image. This is the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater (D), and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. The far wall of the crater shows lighter and darker streaks going down the slopes (C). The presence of material of different brightness on the far crater slopes and in some of the grooves shows that the satellite is heterogeneous (that is, it is made of a mixture of different types of materials). The motion of debris down slopes is guided by gravity, which is only about 1/1000th that of the Earth -- e.g., a 68-kilogram (150- pound) person would weigh only about 57 grams (2 ounces) on Phobos. Previous images from the Viking spacecraft in the 1970's were not of sufficient resolution to show the effectiveness of gravity on Phobos in moving material down slopes.<p>Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01336" onclick="window.open(this.href); return false;" title="Voir l'image PIA01336: High-Resolution MOC Image of Phobos' Face sur le site de la NASA">Voir l'image PIA01336: High-Resolution MOC Image of Phobos' Face sur le site de la NASA.</a></div>
PIA01336: High-Resolution MOC Image of Phobos' Face
<h1>PIA03612: Spirit View of Phobos Eclipse, Sol 675</h1><div class="PIA03612" lang="en" style="width:392px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p><a href="/figures/PIA03612_fig1.jpg"></a><b><br />Annotated Spirit View of Phobos Eclipse, Sol 675</b></p><p>NASA's Mars Exploration Rover Spirit observed the Martian moon Phobos entering the shadow of Mars during the night of the rover's 675th sol (Nov. 27, 2005). The panoramic camera captured 16 images, spaced 10 seconds apart, covering the period from when Phobos was in full sunlight to when it was entirely in shadow. As with our own Moon during lunar eclipses on Earth, even when in the planet's shadow, Phobos was not entirely dark. The small amount of light still visible from Phobos is a kind of "Mars-shine" -- sunlight reflected through Mars' atmosphere and into the shadowed region.</p><p>This view is a time-lapse composite of images taken 20 seconds apart, showing the movement of Phobos from left to right. (At 10 seconds apart, the images of the moon overlap each other.) Scientists are using information about the precise timing of Martian moon eclipses gained from observations such as these to refine calculations about the orbital path of Phobos. The precise position of Phobos will be important to any future spacecraft taking detailed pictures of the moon or landing on its surface.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03612" onclick="window.open(this.href); return false;" title="Voir l'image PIA03612: Spirit View of Phobos Eclipse, Sol 675 sur le site de la NASA">Voir l'image PIA03612: Spirit View of Phobos Eclipse, Sol 675 sur le site de la NASA.</a></div>
PIA03612: Spirit View of Phobos Eclipse, Sol 675
<h1>PIA04521: Martian Moon, Phobos</h1><div class="PIA04521" lang="en" style="width:799px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">MGS MOC Release No. MOC2-362, 16 May 2003<p>Mars has two satellites, Phobos and Deimos. In August and September, 1998, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) had four opportunities for close fly-bys of the inner moon, Phobos. This spectacular view, taken from the MOC archives of over 123,000 images, shows the large crater, Stickney, toward the upper right. Grooves, or troughs, radiate outward from Stickney and are known from Viking and Mariner 9 images to be prevalent all over the surface of Phobos. Sunlight illuminates the scene from the upper right. Another view of Phobos from 1998 can be seen in: MOC2-66, 11 September 1998, "Phobos."<p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA04521" onclick="window.open(this.href); return false;" title="Voir l'image PIA04521: Martian Moon, Phobos sur le site de la NASA">Voir l'image PIA04521: Martian Moon, Phobos sur le site de la NASA.</a></div>
PIA04521: Martian Moon, Phobos
<h1>PIA04589: Phobos Over the Martian Limb</h1><div class="PIA04589" lang="en" style="width:93px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p><a href="/figures/PIA04589_context_lg.jpg"></a>MOC Wide Angle View<p><a href="/figures/PIA04589_phobos_lg.jpg"></a>MOC Narrow Angle Camera View<br><p>MGS MOC Release No. MOC2-400, 23 June 2003<p>Mars has two natural satellites, or moons, Phobos and Deimos. On 1 June 2003, the Mars Global Surveyor (MGS) spacecraft was slewed eastward to capture these views of the inner moon, Phobos, shortly before it set over the afternoon limb. Phobos orbits Mars about 3 times a day at an average distance of 9,378 km (5,828 mi). About 0.006 times the size of Earth's Moon, Phobos is a potato-shaped object with dimensions approximately 27 by 22 by 18 kilometers (about 17 by 14 by 11 miles).<p>The first picture shown here is a color composite of four MGS Mars Orbiter Camera (MOC) wide angle images; the second is the same as the first, but indicates the location of Phobos. The third view is a MOC narrow angle image, taken at the same time as the wide angle views, showing details on the surface of the tiny moon.<p>Phobos is one of the darkest objects in the Solar System. Thus, four wide angle images were obtained to make the picture of Phobos over the martian limb: a pair of red and blue wide angle images was acquired for the limb, and a pair of separate images were required to see Phobos. The wide angle images illustrate the fact that Phobos is mostly colorless (dark gray); the faint orange/red hue in the wide angle picture is a combination of slight differences in the focal lengths of the blue and red cameras and the orange/red illumination provided by reflection of sunlight off Mars. To a person standing on Phobos, the red planet would fill most of the sky.<p>The high resolution image (bottom) was taken at the same time as the wide angle views. MGS was about 9,670 kilometers (6,010 miles) from Phobos when the picture was taken. At this distance, the image resolution is about 36 meters (470 ft.) per pixel; the maximum dimension of Phobos as seen in this image (the diagonal from lower left to upper right) is just over 24 km (15 mi). This is the "trailing" hemisphere, the part of Phobos that faces opposite the direction that the moon orbits Mars. This is a part of Phobos that was not seen by MOC in 1998, when MGS made several close flybys of the tiny moon.<p>The rows of grooves and aligned pits on Phobos are related to, and were probably caused by, a large meteor impact that occurred on the side of Phobos that is not seen here. That large crater, Stickney, was named for the maiden name of the wife of the astronomer that discovered Phobos and the other martian satellite, Deimos, in 1877, Asaph Hall.<p>Examples, with descriptive captions, of the views of Phobos obtained by MOC in 1998 can be seen at:<p><a href="http://www.msss.com/mars_images/moc/9_11_98_phobos_rel/">http://www.msss.com/mars_images/moc/9_11_98_phobos_rel/</a><a href="http://www.msss.com/mars_images/moc/2003/05/16/">http://www.msss.com/mars_images/moc/2003/05/16/</a><p>All of the previous MOC images of Phobos are available in the MOC Gallery at:<p><a href="http://www.msss.com/moc_gallery/ab1_m04/natables/na999.html">http://www.msss.com/moc_gallery/ab1_m04/natables/na999.html</a><a href="http://www.msss.com/moc_gallery/ab1_m04/watables/wa999.html">http://www.msss.com/moc_gallery/ab1_m04/watables/wa999.html</a><p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA04589" onclick="window.open(this.href); return false;" title="Voir l'image PIA04589: Phobos Over the Martian Limb sur le site de la NASA">Voir l'image PIA04589: Phobos Over the Martian Limb sur le site de la NASA.</a></div>
PIA04589: Phobos Over the Martian Limb
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PIA04589_phobos_lg.jpg
<h1>PIA06335: Phobos Viewed from Mars</h1><div class="PIA06335" lang="en" style="width:700px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Taking advantage of extra solar energy collected during the day, NASA's Mars Exploration Rover Spirit settled in for an evening of stargazing, photographing the two moons of Mars as they crossed the night sky. The first two images in this sequence show gradual enhancements in the surface detail of Mars' largest moon, Phobos, made possible through a combination technique known as "stacking." In "stacking," scientists use a mathematical process known as Laplacian sharpening to reinforce features that appear consistently in repetitive images and minimize features that show up only intermittently. In this view of Phobos, the large crater named Stickney is just out of sight on the moon's upper right limb.</p><p>Spirit acquired the first two images with the panoramic camera on the night of sol 585 (Aug. 26,2005). The far right image of Phobos, for comparison, was taken by the High Resolution Stereo Camera on Mars Express, a European Space Agency orbiter. The third image in this sequence was derived from the far right image by making it blurrier for comparison with the panoramic camera images to the left. More information about the Mars Express image is available at <a href="http://www.esa.int/SPECIALS/Mars_Express/SEM21TVJD1E_1.html">http://www.esa.int/SPECIALS/Mars_Express/SEM21TVJD1E_1.html"</a></p><p>Scientists will use images of the two moons to better map their orbital positions, learn more about their composition, and monitor the presence of nighttime clouds or haze.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA06335" onclick="window.open(this.href); return false;" title="Voir l'image PIA06335: Phobos Viewed from Mars sur le site de la NASA">Voir l'image PIA06335: Phobos Viewed from Mars sur le site de la NASA.</a></div>
PIA06335: Phobos Viewed from Mars
<h1>PIA06336: The Two Moons of Mars as Seen from Mars</h1><div class="PIA06336" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Taking advantage of extra solar energy collected during the day, NASA's Mars Exploration Rover Spirit settled in for an evening of stargazing, photographing the two moons of Mars as they crossed the night sky. "It is incredibly cool to be running an observatory on another planet," said planetary scientist Jim Bell of Cornell University, Ithaca, N.Y., lead scientist for the panoramic cameras on Spirit and Opportunity. This time-lapse composite, acquired the evening of Spirit's martian sol 585 (Aug. 26, 2005) from a perch atop "Husband Hill" in Gusev Crater, shows Phobos, the brighter moon, on the right, and Deimos, the dimmer moon, on the left. Tiny streaks mark the trails of background stars moving across the sky or the impact of cosmic rays lighting up random groups of pixels in the image. </p><p>Scientists will use images of the two moons to better map their orbital positions, learn more about their composition, and monitor the presence of nighttime clouds or haze. Spirit took the five images that make up this composite using the panoramic camera's broadband filter, which was designed specifically for acquiring images under low-light conditions.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA06336" onclick="window.open(this.href); return false;" title="Voir l'image PIA06336: The Two Moons of Mars as Seen from Mars sur le site de la NASA">Voir l'image PIA06336: The Two Moons of Mars as Seen from Mars sur le site de la NASA.</a></div>
PIA06336: The Two Moons of Mars as Seen from Mars
<h1>PIA10366: Phobos from 6,800 Kilometers</h1><div class="PIA10366" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the first, taken from a distance of about 6,800 kilometers (about 4,200 miles). The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across.</p><p>The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).</p><p>In the full-resolution version of this image, a pixel encompasses 6.8 meters (22 feet), providing a resolution (smallest visible feature) of about 20 meters (about 65 feet). Although the image is displayed here in black and white, data from HiRISE's three color channels were used to give higher signal-to-noise, thereby increasing detail. The image is in the HiRISE catalog as PSP_007769_9010.</p><p>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 & Technologies Corp., Boulder, Colo.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA10366" onclick="window.open(this.href); return false;" title="Voir l'image PIA10366: Phobos from 6,800 Kilometers sur le site de la NASA">Voir l'image PIA10366: Phobos from 6,800 Kilometers sur le site de la NASA.</a></div>
PIA10366: Phobos from 6,800 Kilometers
<h1>PIA10367: Phobos from 5,800 Kilometers</h1><div class="PIA10367" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the second, taken from a distance of about 5,800 kilometers (about 3,600 miles). The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across.</p><p>The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).</p><p>In the full-resolution version of this image, a pixel encompasses 5.8 meters (19 feet), providing a resolution (smallest visible feature) of about 15 meters (about 50 feet). Previous pictures from NASA's Mars Global Surveyor are of slightly higher resolution, at 4 meters (13 feet) per pixel. However, the HiRISE images have higher signal-to-noise, making the new data some of the best ever for Phobos. </p><p>Although the image is displayed here in black and white, data from HiRISE's three color channels were used to give higher signal-to-noise, thereby increasing detail. The image is in the HiRISE catalog as PSP_007769_9015.</p><p>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 & Technologies Corp., Boulder, Colo.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA10367" onclick="window.open(this.href); return false;" title="Voir l'image PIA10367: Phobos from 5,800 Kilometers sur le site de la NASA">Voir l'image PIA10367: Phobos from 5,800 Kilometers sur le site de la NASA.</a></div>
PIA10367: Phobos from 5,800 Kilometers
<h1>PIA10368: Phobos from 6,800 Kilometers (Color)</h1><div class="PIA10368" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p><a href="/tiff/PIA10368_fig1.tif"></a><br />Inset</p><p>The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the first, taken from a distance of about 6,800 kilometers (about 4,200 miles). It is presented in color by combining data from the camera's blue-green, red, and near-infrared channels. </p><p>The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across. The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. </p><p>The color data accentuate details not apparent in black-and-white images. For example, materials near the rim of Stickney appear bluer than the rest of Phobos. Based on analogy with materials on our own moon, this could mean this surface is fresher, and therefore younger, than other parts of Phobos.</p><p>A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).</p><p>In the full-resolution version of this image, a pixel encompasses 6.8 meters (22 feet), providing a resolution (smallest visible feature) of about 20 meters (about 65 feet). The image is in the HiRISE catalog as PSP_007769_9010.</p><p>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 & Technologies Corp., Boulder, Colo.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA10368" onclick="window.open(this.href); return false;" title="Voir l'image PIA10368: Phobos from 6,800 Kilometers (Color) sur le site de la NASA">Voir l'image PIA10368: Phobos from 6,800 Kilometers (Color) sur le site de la NASA.</a></div>
PIA10368: Phobos from 6,800 Kilometers (Color)
PIA10368_fig1.jpg
PIA10368_fig1.jpg
<h1>PIA10369: Phobos from 5,800 Kilometers (Color)</h1><div class="PIA10369" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is the second, taken from a distance of about 5,800 kilometers (about 3,600 miles). It is presented in color by combining data from the camera's blue-green, red, and near-infrared channels. </p><p>The illuminated part of Phobos seen in the images is about 21 kilometers (13 miles) across. The most prominent feature in the images is the large crater Stickney in the lower right. With a diameter of 9 kilometers (5.6 miles), it is the largest feature on Phobos. </p><p>The color data accentuate details not apparent in black-and-white images. For example, materials near the rim of Stickney appear bluer than the rest of Phobos. Based on analogy with materials on our own moon, this could mean this surface is fresher, and therefore younger, than other parts of Phobos.</p><p>A series of troughs and crater chains is obvious on other parts of the moon. Although many appear radial to Stickney in this image, recent studies from the European Space Agency's Mars Express orbiter indicate that they are not related to Stickney. Instead, they may have formed when material ejected from impacts on Mars later collided with Phobos. The lineated textures on the walls of Stickney and other large craters are landslides formed from materials falling into the crater interiors in the weak Phobos gravity (less than one one-thousandth of the gravity on Earth).</p><p>In the full-resolution version of this image, a pixel encompasses 5.8 meters (19 feet), providing a resolution (smallest visible feature) of about 15 meters (about 50 feet). Previous pictures from NASA's Mars Global Surveyor are of slightly higher resolution, at 4 meters (13 feet) per pixel. However, the HiRISE images have higher signal-to-noise, making the new data some of the best ever for Phobos. This image is in the HiRISE catalog as PSP_007769_9015.</p><p>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 & Technologies Corp., Boulder, Colo.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA10369" onclick="window.open(this.href); return false;" title="Voir l'image PIA10369: Phobos from 5,800 Kilometers (Color) sur le site de la NASA">Voir l'image PIA10369: Phobos from 5,800 Kilometers (Color) sur le site de la NASA.</a></div>
PIA10369: Phobos from 5,800 Kilometers (Color)
<h1>PIA10370: 'Marsshine' on Shadowed Part of Phobos</h1><div class="PIA10370" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p><a href="/tiff/PIA10370_fig1.tif"></a><br />Inset</p><p>The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took two images of the larger of Mars' two moons, Phobos, within 10 minutes of each other on March 23, 2008. This is a portion of the second one, enhanced to bring out detail in areas of Phobos that were not illuminated by the sun when the image was taken. Craters are visible due to faint illumination from reflected light off of Mars ("Marsshine"). This is directly analogous to "Earthshine," the reflected sunlight from our planet that illuminates the dark side of Earth's moon. The enhancement to show details in the shadows also washes out detail in the sunlit areas in the lower portion of the image.</p><p>The ability to see features on Phobos illuminated by Marsshine demonstrates the high sensitivity of the HiRISE camera. This image is in the HiRISE catalog as PSP_007769_9015.</p><p>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 & Technologies Corp., Boulder, Colo.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA10370" onclick="window.open(this.href); return false;" title="Voir l'image PIA10370: 'Marsshine' on Shadowed Part of Phobos sur le site de la NASA">Voir l'image PIA10370: 'Marsshine' on Shadowed Part of Phobos sur le site de la NASA.</a></div>
PIA10370: 'Marsshine' on Shadowed Part of Phobos
PIA10370_fig1.jpg
PIA10370_fig1.jpg