This photo taken in the "Mars Yard" at NASA's Jet Propulsion Laboratory, Pasadena, California, on Aug. 1, 2017, shows a step in development of possible alternative techniques that NASA's Curiosity Mars rover might be able to use to resume drilling into rocks on Mars. In late 2016, after Curiosity's drill had collected sample material from 15 Martian rocks in four years, the drill's feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock. In the alternative technique seen here, called "feed-extended drilling," the test rover's stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill's feed mechanism. https://photojournal.jpl.nasa.gov/catalog/PIA22062

In the summer and fall of 2017, the team operating NASA's Curiosity Mars rover conducted tests in the "Mars Yard" at NASA's Jet Propulsion Laboratory, Pasadena, California, to develop techniques that Curiosity might be able to use to resume drilling into rocks on Mars. JPL robotics engineer Vladimir Arutyunov, in this June 29, 2017, photo, checks the test rover's drill bit at its contact point with a rock. Note that the stabilizer post visible to the right of the bit is not in contact with the rock, unlike the positioning used and photographed by Curiosity when drilling into rocks on Mars in 2013 to 2016. In late 2016, after Curiosity's drill had collected sample material from 15 Martian rocks, the drill's feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to the stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock. In the alternative technique seen here, called "feed-extended drilling," the test rover's stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill's feed mechanism. https://photojournal.jpl.nasa.gov/catalog/PIA22061

jsc2024e031840 --- NASA astronaut Kate Rubins (right) takes a photo of NASA astronaut Andre Douglas (left) as he raises an American flag during a simulated moonwalk in a rock yard at NASA’s Johnson Space Center. Credit: NASA/Josh Valcarcel

Scarecrow, a mobility-testing model for NASA Mars Science Laboratory, easily traverses large rocks in the Mars Yard testing area at NASA Jet Propulsion Laboratory.

Megabreccia is a term used to describe jumbled, fragmented blocks of rock larger than 1 meter 1.09 yard across. This image was observed by NASA Mars Reconnaissance Orbiter.

Date: 03-02-2021 Location: JSC Rockyard Subject: Scott Wray rewiews test documents during Lunar Exploration EVA Night Operations at Johnson Space Center's Rock Yard. Photographer: James Blair

Test subjects Kelsey Young and Tess Caswell evaluate lunar field geology tasks as part of the Exploration Extravehicular Activity (xEVA) night operations development tests conducted at Johnson Space Center’s Rock Yard.

A development rover that is part of NASA's CADRE (Cooperative Autonomous Distributed Robotic Exploration) technology demonstration drives over a rock during its first autonomous drive around the Mars Yard at the agency's Jet Propulsion Laboratory in Southern California in June 2023. Under a canopy behind the rover are, from left, graduate student intern Natalie Deo and CADRE verification and validation lead Sawyer Brooks of JPL. The CADRE team successfully tested a new wheel design, surface navigation software, and mobility capabilities, among other aspects of the project. The rover being tested is similar in size and appearance to the flight models of the CADRE rovers, which are still being built. Slated to arrive at the Moon in spring 2024 as part of NASA's CLPS (Commercial Lunar Payload Services) initiative, CADRE is designed to demonstrate that multiple robots can cooperate and explore together autonomously – without direct input from human mission controllers. A trio of the miniature solar-powered rovers, each about the size of a carry-on suitcase, will explore the Moon as a team, communicating via radio with each other and a base station aboard a lunar lander. By taking simultaneous measurements from multiple locations, CADRE will also demonstrate how multirobot missions can record data impossible for a single robot to achieve – a tantalizing prospect for future missions. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA25667

The full-scale engineering model of NASA's Perseverance rover has put some dirt on its wheels. This vehicle system test bed (VSTB) rover moved into its home — a garage facing the Mars Yard at NASA's Jet Propulsion Laboratory in Southern California — on Sept. 4, 2020. It drove onto simulated Martian surface of the Mars Yard — a dirt field at JPL studded with rocks and other obstacles — for the first time on Sept. 8. The VSTB rover is also known as OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars). A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will also characterize the planet's climate and geology, pave the way for human exploration of the Red Planet, and be the first planetary spacecraft to collect and cache Martian rock and regolith (broken rock and dust). Subsequent missions, currently under consideration by NASA in cooperation with the European Space Agency, would send spacecraft to Mars to collect these cached samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 mission is part of a larger program that includes missions to the Moon as a way to prepare for human exploration of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will establish a sustained human presence on and around the Moon by 2028 through NASA's Artemis lunar exploration plans. https://photojournal.jpl.nasa.gov/catalog/PIA23966

ISS002-E-5627 (23 April 2001) --- Algecira (left), the Bay of Gibraltar (Bahia de Algecira) and "The Rock of Gibraltar" (right) are featured in this detailed vertical view on the European side of the Strait of Gibraltar. Ship traffic in the Bay and Gibraltar Dock Yard can easily be seen. This digital still camera's image is part of a series of pictures centering on the Strait of Gibraltar area which was recorded by the ISS Expedition Two crew on April 23, 2001.

The engineering models of both the Curiosity Mars rover (foreground) and the Perseverance Mars rover share space in the recently expanded garage at the Mars Yard. Curiosity's Earthy double is called MAGGIE, short for Mars Automated Giant Gizmo for Integrated Engineering; Perseverance's double goes by OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars). The Mars Yard simulates Martian terrain and has served as a testing ground for many fully-engineered rover twins – from the very first, tiny Sojourner that landed on Mars in 1997 to the Spirit and Opportunity missions that began in 2004 to the Curiosity and Perseverance rovers exploring Mars today. Each is generically referred to as a vehicle system test bed. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. https://photojournal.jpl.nasa.gov/catalog/PIA24525

Engineers use OPTIMISM, a full-size replica of NASA's Perseverance rover, to test how it will deposit its first sample tube on the Martian surface. The test was conducted in the Mars Yard at NASA's Jet Propulsion Laboratory in Southern California. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA25676

Short for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars, OPTIMISM faces a doorway of the Mars Yard garage at NASA's Jet Propulsion Laboratory on Oct. 29, 2021. Referred to generically as a vehicle system test bed, OPTIMISM was recently updated with additional mobility software and the bulk of the complex sample caching system. As with vehicle system test beds for other Mars rovers, OPTIMISM is used to test moves and scenarios in the Mars Yard's simulated Red Planet landscape to help ensure that its twin on Mars can safely execute the commands sent by Earth-bound controllers. The tests could also potentially reveal unexpected problems Perseverance might encounter. With longer drives in Perseverance's near future, another job for OPTIMISM will involve presenting new challenges to the rover's autonomous navigation system, or AutoNav. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. https://photojournal.jpl.nasa.gov/catalog/PIA24527

Updated with new features, including additional mobility software and the bulk of the sample caching system, the Earthly twin of NASA's Perseverance Mars rover arrives at the Mars Yard garage at the agency's Jet Propulsion Laboratory on Oct. 29, 2021. The vehicle is generically referred to as a vehicle system test bed but goes by the name OPTIMISM (short for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars). As with vehicle system test beds for other Mars rovers, OPTIMISM is used to test moves and scenarios in the Mars Yard's simulated Red Planet landscape to help ensure that its twin on Mars can safely execute the commands sent by Earth-bound controllers. The tests could also potentially reveal unexpected problems Perseverance might encounter. With longer drives in Perseverance's near future, another job for OPTIMISM will involve presenting new challenges to the rover's autonomous navigation system, or AutoNav. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. https://photojournal.jpl.nasa.gov/catalog/PIA24528

On Oct. 29, 2021, a heavy-duty vehicle transports the Perseverance rover's engineering model from a test lab to the Mars Yard garage at NASA's Jet Propulsion Laboratory. Short for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars, OPTIMISM is generically referred to as a vehicle system test bed. As with vehicle system test beds for other Mars rovers, OPTIMISM is used to test moves and scenarios in the Mars Yard's simulated Red Planet landscape to help ensure that its twin on Mars can safely execute the commands sent by Earth-bound controllers. The tests could also potentially reveal unexpected problems Perseverance might encounter. With longer drives in Perseverance's near future, another job for OPTIMISM will involve presenting new challenges to the rover's autonomous navigation system, or AutoNav. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. https://photojournal.jpl.nasa.gov/catalog/PIA24526

Technicians move a full-scale engineering version of NASA's Perseverance Mars rover into to its new home — a garage facing the Mars Yard at the agency's Jet Propulsion Laboratory in Southern California — on Sept. 4, 2020. This vehicle system test bed (VSTB) rover was built in a warehouselike assembly room not far from the Mars Yard — an area that simulates the Red Planet's surface — and enables the mission team to test how hardware and software will perform before they transmit commands to the real rover on Mars. It also goes by the name OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars). The Perseverance rover's astrobiology mission will search for signs of ancient microbial life. It will also characterize the planet's climate and geology, pave the way for human exploration of the Red Planet, and be the first planetary mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent missions, currently under consideration by NASA in cooperation with the European Space Agency, would send spacecraft to Mars to collect these cached samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 mission is part of a larger program that includes missions to the Moon as a way to prepare for human exploration of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will establish a sustained human presence on and around the Moon by 2028 through NASA's Artemis lunar exploration plans. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA23965

Engineers react with surprise while testing how NASA's Perseverance rover will deposit its sample tubes on the Martian surface. Less than 5% of the time, a flat end on the sample tube caused it to land straight up after dropping. This test was conducted using OPTIMISM, a full-scale replica of Perseverance, in the Mars Yard at NASA's Jet Propulsion Laboratory in Southern California. Perseverance has been taking duplicate samples from each rock target the mission selects. After depositing one sample on the surface Dec. 21, 2022, the rover has 17 samples in its belly, including one atmospheric sample. Based on the architecture of the Mars Sample Return campaign, the rover would deliver samples to a robotic lander carrying a small rocket that would blast them off to space. The depot will serve as a backup if Perseverance can't deliver its samples. In that case, a pair of Sample Recovery Helicopters would be called upon to pick up the sample tubes and deliver them to the lander. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust). Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA25677

The Kunlun fault is one of the gigantic strike-slip faults that bound the north side of Tibet. Left-lateral motion along the 1,500-kilometer (932-mile) length of the Kunlun has occurred uniformly for the last 40,000 years at a rate of 1.1 centimeter per year, creating a cumulative offset of more than 400 meters (1300 feet). In this image, two splays of the fault are clearly seen crossing from east to west. The northern fault juxtaposes sedimentary rocks of the mountains against alluvial fans. Its trace is also marked by lines of vegetation, which appear red in the image. The southern, younger fault cuts through the alluvium. A dark linear area in the center of the image is wet ground where groundwater has pounded against the fault. Measurements from the image of displacements of young streams that cross the fault show 15 to 75 meters (16 to 82 yards) of left-lateral offset. This image of Tibet covers an area 40 kilometers (25 miles) wide and 15 kilometers (10 miles) long in three bands of the reflected visible and infrared wavelength region. ASTER acquired the scene on July 20, 2000. The image is located at 35.8 degrees north latitude and 93.6 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA02658

The full-scale engineering model of NASA's Perseverance rover raises its "head," or remote sensing mast, at NASA's Jet Propulsion Laboratory in Southern California. This model is known as the vehicle system test bed (VSTB) rover, or OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars). OPTIMISM raised its mast shortly after moving into its new home at JPL's Mars Yard on Sept. 4, 2020. The mast hosts many of the rover's cameras and scientific instruments. At the top of the mast, the large circular opening is where the SuperCam instrument will be installed on this test rover. Also visible in these images below the SuperCam "eye" are the navigation cameras (two cameras closest to the outside of the head) and the Mastcam-Z cameras inside of the navigation cameras. A key objective for Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will also characterize the planet's climate and geology, pave the way for human exploration of the Red Planet, and be the first planetary spacecraft to collect and cache Martian rock and regolith (broken rock and dust). Subsequent missions, currently under consideration by NASA in cooperation with the European Space Agency, would send spacecraft to Mars to collect these cached samples from the surface and return them to Earth for in-depth analysis. The Mars 2020 mission is part of a larger program that includes missions to the Moon as a way to prepare for human exploration of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will establish a sustained human presence on and around the Moon by 2028 through NASA's Artemis lunar exploration plans. https://photojournal.jpl.nasa.gov/catalog/PIA23967

A vantage point on "Vera Rubin Ridge" provided NASA's Curiosity Mars rover this detailed look back over the area where it began its mission inside Gale Crater, plus more-distant features of the crater. This view toward the north-northeast combines eight images taken by the right-eye, telephoto-lens camera of Curiosity's Mast Camera (Mastcam). It shows more detail of a fraction of the area pictured in a more sweeping panorama (see PIA22210) acquired from the same rover location using Mastcam's left-eye, wider-angle-lens camera. The scene has been white-balanced so the colors of the rock materials resemble how they would appear under daytime lighting conditions on Earth. The component images were taken on Oct. 25, 2017, during the 1,856th Martian day, or sol, of the rover's work on Mars. At that point, Curiosity had gained 1,073 feet (327 meters) in elevation and driven 10.95 miles (17.63 kilometers) from its landing site. Mount Sharp stands about 3 miles (5 kilometers) high in the middle of Gale Crater, which spans 96 miles (154 kilometers) in diameter. Vera Rubin Ridge is on the northwestern flank of lower Mount Sharp. The right foreground of this panorama shows a portion of Vera Rubin Ridge. In the distance is the northern wall of Gale Crater, with the rim crest forming the horizon roughly 25 miles (40 kilometers) from the rover's location. An annotated version, Figure 1, indicates where the rover landed (at "Bradbury Landing") in 2012 and the initial portion of its drive, including investigation sites "Yellowknife Bay," "Darwin" and "Cooperstown." The rover's exact landing site is hidden behind a slight rise. The heat shield, back shell, and parachute used during the spacecraft's descent are within the pictured area but not recognizable due to the distance and to camouflaging by dust. At Yellowknife Bay in 2013, the mission found evidence of an ancient freshwater-lake environment that offered all of the basic chemical ingredients for microbial life. Figure 2 includes three scale bars: of 40 meters (131 feet) at a distance of about 1,530 meters (1,673 yards) near the base of Mount Sharp; of 1,500 meters (1,640 yards) at a distance of about 30.75 kilometers (19.1 miles) near the base of the crater wall; and of 2,000 meters (1.2 miles) at a distance of about 41.2 kilometers (25.6 miles) at the crest of the rim. Annotated images are available at https://photojournal.jpl.nasa.gov/catalog/PIA22209

Climbing "Vera Rubin Ridge" provided NASA's Curiosity Mars rover this sweeping vista of the interior and rim of Gale Crater, including much of the rover's route during its first five-and-a-half years on Mars and features up to about 50 miles (85 kilometers) away. The scene spans from southwest on the left to northeast on the right, combining 16 side-by-side images taken by the left-eye, wider-angle-lens camera of Curiosity's Mast Camera (Mastcam). It has been white-balanced so the colors of the rock materials resemble how they would appear under daytime lighting conditions on Earth. The component images were taken on Oct. 25, 2017, during the 1,856th Martian day, or sol, of the rover's work on Mars. At that point, Curiosity had gained 1,073 feet (327 meters) in elevation and driven 10.95 miles (17.63 kilometers) from its landing site. Mount Sharp stands about 3 miles (5 kilometers) high in the middle of Gale Crater, which spans 96 miles (154 kilometers) in diameter. Vera Rubin Ridge is on the northwestern flank of lower Mount Sharp. The foreground of this panorama shows portions of lower Mount Sharp. The middle distance shows the floor of Gale Crater. Most of the horizon is formed by the crater's rim. The top of the rim is about 1.2 miles (2 kilometers) higher than the rover's position. On the horizon near the center of the image is a glimpse outside of Gale Crater, to a peak about 50 miles (85 kilometers) from the rover. An annotated version, Figure 1, indicates the rover's approximate path since its 2012 landing, identifies some of the sites it has investigated along the way, such as "Yellowknife Bay," "The Kimberley," "Namib Dune" and "Murray Buttes"; and points out other geological features visible in the scene, such as the channel of Peace Vallis, an ancient streambed descending from the crater rim. The relative positions of the labeled features are also mapped on an accompanying orbital view in PIA22208, with two areas color-coded for ease of matching them in the annotated panorama and the orbital view. Figure 2 is a version with a white-line box indicating the smaller area covered in a more-detailed vista (see PIA22209) taken from this same rover location by Mastcam's right-eye, telephoto-lens camera. It also includes three scale bars: of 50 meters (164 feet) at a distance of 1,170 meters (1,280 yards) near the base of Mount Sharp; of 1,000 meters (1,094 yards) at a distance of about 23.4 kilometers (14.5 miles) near the base of the crater wall; and of 2 kilometers (1.2 miles) at a distance of about 31.5 kilometers (19.6 miles) at the crest of the rim. Annotated images are available at https://photojournal.jpl.nasa.gov/catalog/PIA22210

ISS034-E-057550 (28 Feb. 2013) --- One of the Expedition 34 crew members aboard the Earth-orbiting International Space Station photographed this image featuring the Southern High Plains of northwestern Texas, directly south of the city of Amarillo (off the image to the north). At first glance the picture appears more like a map than an actual photo. The winter of 2012-2013 has been marked by powerful snowstorms with record-setting snowfall throughout much of the Midwestern United States The snowstorm that passed through this area left a record snowfall of approximately 43 centimeters (17 inches). Snow blankets the city of Canyon, Texas. Urban street grids and stream channels appear etched into the landscape by the snow, a result of both melting and street clearing in the urban regions and of the incised nature of stream channels in the surrounding plains. Agricultural fields are easily identified due to the even snow cover broken only by roadways between the fields. Palo Duro Canyon is largely free of snow along the Prairie Dog Town Fork of the Red River channel and at lower elevations, allowing the red sedimentary rocks of the canyon walls to be visible. Lake Tanglewood, a reservoir to the northeast of Canyon, appears dark due to a lack of ice cover. Another dark region to the northwest of Canyon is a feed yard for cattle; any snowfall in this area has been removed by the actions of the livestock. The image was recorded with a digital camera using a 400 millimeter lens,

The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed specifically to provide images of Mars that have a resolution comparable to the aerial photographs commonly used by Earth scientists to study geological processes and map landforms on our home planet. When MGS reaches its Mapping Orbit in March 1999, MOC will be able to obtain pictures with spatial resolutions of 1.5 meters (5 feet) per pixel--this good enough to easily see objects the size of an automobile. Boulders are one of the keys to determining which processes have eroded, transported, and deposited material on Mars (e.g.,landslides, mud flows, flood debris). During the first year in orbit,MGS MOC obtained pictures with resolutions between 2 and 30 meters (7to 98 feet) per pixel. It was found that boulders are difficult to identify on Mars in images with resolutions worse than about 2-3 meters per pixel. Although not known when the MOC was designed,"thresholds" like this are found on Earth, too. The MOC's 1.5 m/pixel resolution was a compromise between (1) the anticipation of such resolution-dependent sensitivity based on our experience with Earth and (2)the cost in terms of mass if we had built a larger telescope to get a higher resolution. Some rather larger boulders (i.e., larger than about 10 meters--or yards--in size) have already been seen on Mars by the orbiting camera. This is a feat similar to that which can be obtained by "spy" satellites on Earth. The MOC image 53104 subframe shown above features a low, rounded hill in southeastern Utopia Planitia. Each of the small, lumpy features on the top of this hill is a boulder. In this picture, boulders are not seen on the surrounding plain. These boulders are interpreted to be the remnants of a layer of harder rock that once covered the top of the hill, but was subsequently eroded and broken up by weathering and wind processes. MOC image 53104 was taken on September 2, 1998. The subframe shows an area 2.2 km by 3.3 km (1.4 miles by 2.7 miles). The image has a resolution of about 3.25 meters (10.7 feet) per pixel. The subframe is centered at 41.0°N latitude and 207.3°W longitude. North is approximately up, illumination is from the left. http://photojournal.jpl.nasa.gov/catalog/PIA01500