Sand Ripples in a Tyrrhena Terra Valley

Enigmatic, shallowly incised valleys are found in some mid- to low-latitude regions on Mars. These valleys are very different in appearance compared to the very old, large, and well-developed valley networks on Mars.

The effects of liquid water or ice on a landscape are a distinctive indicator of past climate, and further insight into the age and origin of these shallow valleys may help advance our understanding of the environment in which they formed and potential late-stage habitability of Mars.

The shallow valley has been filled with small, transverse aeolian ripples (TARS) oriented perpendicular to the valley walls.

This is a stereo pair with ESP_031751_1410.

Photo credit: NASA/JPL/University of Arizona

Active Slope Flows in Hale Crater

HiRISE has been monitoring steep slopes on Mars because some of them reveal active processes. In some cases, there are many seasonal flows on warm slopes, suggesting some role for water in their activity.

The central hills in Hale Crater is one such location, with thousands of seasonal flows on steep slopes below bedrock outcrops. The cutout shows a small sample of this image, with relatively dark and reddish lines extending onto sediment fans.

These lines grow slowly over several months time, fade and disappear in the cold season (southern winter), then reform the next warm season (southern spring and summer).

Photo credit: NASA/JPL/University of Arizona

Endeavour Crater's Western Rim (DTM)

This digital terrain model covers the western rim of Endeavour Crater where the Mars Exploration Rover Opportunity has been investigating since 2011. It provides valuable topographic data that have been very useful in Opportunity mission planning.

For example, this subimage shows a northward perspective view of HiRISE and compositional data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) overlaid over the DTM of Endeavour Crater. This image shows where orbital data indicate possible clay (red), sulfate (green), and volcanic (blue) minerals are located, where the former two attest to the regions aqueous ancient past.

Ongoing surface operations by Opportunity are attempting to reveal the geologic history at Endeavour crater.

Opportunity is currently (2013) at Cape York heading south.

Image credit: NASA/JPL/University of Arizona/USGS

Bashkaus Valles

From the USGS Astrogeology Science Center:

The IAU Working Group for Planetary System Nomenclature has approved the name Bashkaus Valles for a valley system on Mars. For more information, see the map of MC-19 in the Gazetteer of Planetary Nomenclature.

Point Lake Outcrop

This mosaic view from the Mast Camera (Mastcam) on NASA's Mars rover Curiosity shows textural characteristics and shapes of an outcrop called "Point Lake." The outcrop is about 20 inches (half a meter) high and pockmarked with holes. Curiosity recorded the 20 component images for this mosaic on the mission's 302nd Martian day, or sol, (June 12, 2013), during a second approach to Point Lake. The rover used the Mastcam's right-eye camera, which has a telephoto lens.

Point Lake first caught the interest of Curiosity's science team in October and November of 2012, when the outcrop stood out in images taken during the rover's trek eastward to "Yellowknife Bay." Point Lake is conspicuous in the right third of a scene from that time period at PIA16453. It consists of a relatively horizontal surface that ends in a steeper slope, shadowed in that 2012 view. The camera perspective made it look as if there are two steps, but they are actually at the same elevation as each other.

Point Lake stood out for two reasons. First, it forms a small cliff. Geologists love cliffs because they offer a sense of how a rock unit differs from bottom to top. Second, as Curiosity drove closer to Point Lake on the route to Yellowknife Bay, images revealed that the outcrop is full of holes. Holes form in rocks by diverse mechanisms. Identifying which mechanism can provide understanding about the rock and its history. Curiosity parked near Point Lake in November and gained a good view of the top part (PIA16447), but not of the vertical face. Months later, while at the "John Klein" rock-drilling site in Yellowknife Bay, the rover recorded a face-on view of Point Lake (PIA17071). Still, the holes remained puzzling, so the science team decided to get a closer look at Point Lake after leaving Yellowknife Bay. The Sol 302 image is one result.

This image shows that the upper and lower parts of Point Lake differ. The upper part has more holes and is more resistant to weathering. The holes range from smaller than pea size to larger than golf-ball size. They are circular to elliptical in shape. Some of the larger holes have raised rims, as if the material immediately around a hole is slightly more resistant than material farther from the hole. At the right-hand end of the outcrop are a few stones that look as if they could have fallen out of holes in the rock face. At least one of these looks like a thin, curved lining that could have coated the interior of a hole. Embedded nearby in the rock face is a larger rounded rock that has a rock lining around it.

Curiosity's science team is considering diverse geological processes -- both igneous and sedimentary -- as explanations for the holes and other characteristics of Point Lake.

Igneous rocks commonly have holes called vesicles, which are frozen gas bubbles left over from when the rock was molten or fluidized. However, it is also possible to create holes in sedimentary rocks. The easiest way is for pebbles or cobbles in the rock to fall out as the rock erodes, leaving holes in the remaining rock. This is more likely to occur if the pebbles or cobbles are much harder than the surrounding rock.

Holes in either igneous of sedimentary rock can later be partly or wholly filled with secondary minerals delivered by fluids or gases. The secondary minerals that fill the holes are sometimes harder than the host rock, so that when the entire assemblage starts to erode, they remain behind as round nodules. Geodes are an example of this process.

This view is presented in raw color, which shows the scene's colors under Mars lighting conditions as they would look in a typical smart-phone camera photo. Views with white-balanced color, which shows what the rocks would look if they were on Earth, are also available without (Figure 1) and with (Figure 2) scale bars for two different parts of the scene.

Image credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA17267: Detail in "Point Lake" Outcrop.

Nobbys Head

NASA's Mars Exploration Rover Opportunity used its panoramic camera (Pancam) to record this view of the rise in the foreground, called "Nobbys Head." The rover drove around the north and west sides of Nobbys Head during a multi-week southward drive between two raised segments of the west rim of Endeavour Crater. This view is centered toward the south-southeast, with Opportunity's next destination, "Solander Point," toward the right edge of the view.

Nobbys Head is about a third of the way from the rim segment where Opportunity worked for most of the past two years, "Cape York," to Solander Point. See PIA17072 for a map of this section of the rim of Endeavour Crater. Opportunity began a trek of approximately 1.2 miles (2 kilometers) from part of Cape York to Solander Point in late May 2013. The six Pancam frames combined into this mosaic view were taken during the 3,335th Martian day, or sol, of Opportunity's mission on Mars (June 11, 2013). The rover drove 114.4 feet (34.88 meters) on that sol.

Opportunity has been studying the western rim of Endeavour Crater since arriving there in August 2011. The crater spans 14 miles (22 kilometers) in diameter, by far the largest that Opportunity has visited since it landed on Mars in January 2004.

Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State University

Note: For an anaglyph version of this image, see PIA17266: 'Nobbys Head' on Opportunity's Southward Route (Stereo).

Hydrae Chasma

This VIS image shows the eastern part of Hydrae Chasma.

Orbit Number: 50199 Latitude: -6.6969 Longitude: 298.127 Instrument: VIS Captured: 2013-04-08 09:21

Photo credit: NASA/JPL-Caltech/Arizona State University

Rocknest in Gale Crater

This image is a scaled-down version of a full-circle view which combined nearly 900 images taken by NASA's Curiosity Mars rover. The Full-Res TIFF and Full-Res JPEG provided in the top right legend are smaller resolution versions of the 1.3 billion pixel version for easier browser viewing and downloading. Viewers can explore the full-circle image with pan and zoom controls at http://mars.nasa.gov/bp1/.

The view is centered toward the south, with north at both ends. It shows Curiosity at the "Rocknest" site where the rover scooped up samples of windblown dust and sand. Curiosity used three cameras to take the component images on several different days between October 5 and November 16, 2012.

This first NASA-produced gigapixel image from the surface of Mars is a mosaic using 850 frames from the telephoto camera of Curiosity's Mast Camera instrument, supplemented with 21 frames from the Mastcam's wider-angle camera and 25 black-and-white frames -- mostly of the rover itself -- from the Navigation Camera. It was produced by the Multiple-Mission Image Processing Laboratory (MIPL) at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

This version of the panorama retains "raw" color, as seen by the camera on Mars under Mars lighting conditions. A white-balanced version is available at PIA16918. The view shows illumination effects from variations in the time of day for pieces of the mosaic. It also shows variations in the clarity of the atmosphere due to variable dustiness during the month while the images were acquired.

NASA's Mars Science Laboratory project is using Curiosity and the rover's 10 science instruments to investigate the environmental history within Gale Crater, a location where the project has found that conditions were long ago favorable for microbial life.

Image credit: NASA/JPL-Caltech/MSSS

Note: For more information, see Billion-Pixel View of Mars Comes From Curiosity Rover; also PIA16918: Billion-Pixel View From Curiosity at Rock Nest, White-Balanced.

Oraibi Crater

Oraibi crater is about 32 km across and situated in Ares Vallis on Mars. The crater is filled with sediments and its southern rim has been eroded by water. The image was acquired by Mars Express at about 16°N/327°E during orbit 9393 on 11 May 2011. The images have a ground resolution of 15 m per pixel. The image was derived from the nadir channel, which provides the highest detail of all the channels.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Melas Chasma

On 2 May 2004, the High-Resolution Stereo Camera (HRSC) on board the ESA Mars Express spacecraft obtained images from the central area of the Mars canyon called Valles Marineris. The images were taken at a resolution of approximately 16 meters per pixel. The displayed region is located at the southern rim of the Melas Chasma at Mars latitude 12°S and Mars longitude 285°E. The images were taken on orbit 360 of Mars Express.

This perspective view was created by using the stereo channels of the HRSC to produce a digital model of the terrain.

Image credit: ESA/DLR/FU (G. Neukum)

Linear Gullies in Matara Crater

These examples of one distinctive type of Martian gullies, called "linear gullies," are on a dune in Matara Crater, seen at different times of year to observe changes. The observations support a new hypothesis that chunks of frozen carbon dioxide, also known as "dry ice," may create linear gullies. In early Martian spring at some latitudes, dry-ice blocks may glide down sandy slopes on self-generated cushions of sublimating carbon-dioxide gas, plowing the grooves as they go and sometimes leaving pits where they stop sliding and sublimate away.

The three images were taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter, of a site at 49.4 degrees south latitude, 34.7 degrees east longitude. The top image is from Mars southern-hemisphere early summer. The middle image is from the start of spring not quite two Martian years later. The white arrow points out a frost block, which appears very bright against the defrosting dune surface. The bottom image is from later the same spring. Black arrows indicate regions where new channels and pits appeared during the intervening seasons since the top image was taken. The scale bar is 50 meters (55 yards).

The three images are excerpts from HiRISE observations cataloged as ESP_013834_1300 (taken July 9, 2009); ESP_029038_1305 (taken October 6, 2012) and ESP_029961_1305 (taken December 17, 2012).

Image credit: NASA/JPL-Caltech/University of Arizona

Note: For more information, see Marks on Martian Dunes May Reveal Tracks of Dry-Ice Sleds.

MRO Scanning Martian Atmospheric Temperatures

This graphic depicts the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter measuring the temperature of a cross section of the Martian atmosphere as the orbiter passes above the south polar region.

The Mars Climate Sounder is an infrared radiometer that can be pointed sideways for detecting temperatures at different elevations above the surface of the planet. Multiple measurements since MRO arrived at Mars in 2006 have provided a record of atmospheric temperatures at different times of day on both the sunlit (daytime) and dark (nighttime) portions of the planet.

The data indicate that temperatures rise and fall not just once a day, as might be expected from simple warming by the sun, but twice, with a rise during the nighttime as well as during daytime. Researchers have identified the cause for this pattern to be the thin water-ice clouds that form in the equatorial region of Mars. The water-ice clouds absorb infrared light emitted from the Martian surface, and that absorption heats the middle atmosphere.

In the graphic, orange and yellow represent higher temperature than green or blue. These results are described in a paper being published by the journal Geophysical Research Letters.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm.

Linear Gullies Inside Russell Crater

Several types of downhill flow features have been observed on Mars. This image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter is an example of a type called "linear gullies." Linear gullies are characterized by relatively constant width and by raised banks or levees along the sides. Unlike gullies caused by water-lubricated flows on Earth and possibly on Mars, they don't have aprons of debris at the downhill end of the channel. The grooves shown here, on the side of a large sand dune inside Russell Crater, are the longest linear gullies known, extending almost 1.2 miles (2 kilometers) down this dune slope.

New research points to chunks of frozen carbon dioxide, commonly called "dry ice," creating linear gullies by gliding down sandy slopes on cushions of carbon-dioxide gas sublimating from the dry ice. Linear gullies are on mid-latitude sandy slopes, where the ground is covered with carbon-dioxide frost in Martian winter. Before-and-after pairs of HiRISE images indicate that the linear gullies are formed during early spring. Some linear gullies -- such as the ones in the magnified section of this image shown as Figure 1 -- have pits at the downhill end that could be caused by a block of dry ice ending its slide and resting in place as it sublimates away.

This image is a portion of the HiRISE exposure cataloged as PSP_001440_1255 taken on November 16, 2006, at 54.25 degrees south latitude, 12.92 degrees east longitude.

Photo credit: NASA/JPL-Caltech/University of Arizona

Note: For more information, see Marks on Martian Dunes May Be Tracks of Dry-Ice Sleds; also, Dry Ice "Snowboards" on Mars.

Solander Point

NASA's Mars Exploration Rover Opportunity used its panoramic camera (Pancam) to acquire this view of "Solander Point" during the mission's 3,325th Martian day, or sol (June 1, 2013). The southward-looking scene, presented in true color, shows Solander Point on the center horizon, "Botany Bay" in the foreground, and "Cape Tribulation" in the far background at left.

Botany Bay is a topographic saddle exposing sedimentary rocks that are part of the Burns formation, a geological unit Opportunity examined during earlier years of the mission. At Botany Bay, the Burns formation is exposed between isolated remnants of Endeavour Crater's rim. Solander Point and Cape Tribulation are rim segments south of Botany Bay. Opportunity is on the way to Solander Point to spend the upcoming winter season on northerly tilted surfaces. Extensive rock strata are evident on the northern side of Solander Point, and these ancient rocks and surrounding bench materials will be investigated in detail by Opportunity as part of the winter science campaign.

The false-color versions make some differences among geological materials easier to distinguish; these images combine three exposures taken through Pancam filters centered at wavelengths of 753 nanometers, 535 nanometers and 432 nanometers, displayed as red, green and blue colors.

Image credit: NASA/JPL-Caltech/Cornell Univ./Arizona State University

Note: For more information, see Mars Rover Opportunity Trekking Toward More Layers.

Kasei Valles

This mosaic, which features the spectacular Kasei Valles, comprises 67 images taken with the High Resolution Stereo Camera on ESA’s Mars Express. The mosaic spans 987 km north–south (19–36°N) and 1550 km east–west (280–310°E).

Image credit: ESA/DLR/FU Berlin (G. Neukum)

Planum Boreum

The north polar ice cap of Mars, presented as a mosaic of 57 separate images from the High Resolution Stereo Camera on ESA’s Mars Express. The ice cap spans approximately 1000 km and is seen here in polar stereographic projection. The images were taken throughout the entire mission, when Mars Express was at its closest to Mars along its orbit, at about 300-500 km altitude.

The mosaic was published as space science image of the week on the occasion of the tenth anniversary since the mission launched on 2 June 2003.

Image credit: ESA/DLR/FU Berlin–G. Neukum); image processing by F. Jansen (ESA)

Seven Newly-Named Craters

From the USGS Astrogeology Science Center:

The Working Group for Planetary System Nomenclature has approved new names for seven craters on Mars: Asau, Gunjur, Kalba, Neves, Obock, Quthing, and Wafra. For more information, see the Gazetteer of Planetary Nomenclature.

Celebrating Ten Years of Mars Express

The journey of Mars Express, from drawing board through launch, to its key science highlights during ten years of operations.

With its suite of seven instruments, Mars Express has studied the subsurface of the Red Planet to the upper atmosphere and beyond to the two tiny moons Phobos and Deimos, providing an in depth analysis of the planet's history and returning stunning 3D images.

Video credit: ESA; text credit: ESA

Note: For more information, see Ten Years at Mars: New Global Views Plot the Red Planet’s History; also, Mars Express: Ten Years in Orbit.

Roddy and Luba Craters

From the USGS Astrogeology Science Center:

The Working Group for Planetary System Nomenclature has approved new names for two craters on Mars: Roddy and Luba. For more information, see the Gazetteer of Planetary Nomenclature.

Mars Mineral Globe

This unique atlas comprises a series of maps showing the distribution and abundance of minerals formed in water, by volcanic activity, and by weathering to create the dust that makes Mars red. Together the maps provide a global context for the dominant geological processes that have defined the planet’s history.

The maps were built from ten years of data collected by the OMEGA visible and infrared mineralogical mapping spectrometer on Mars Express.

The animation cycles through maps showing: individual sites where a range of minerals that can only be formed in the presence of water were detected; maps of olivine and pyroxene, minerals that tell the story of volcanism and the evolution of the planet’s interior; and ferric oxide and dust. Ferric oxide is a mineral phase of iron, and is present everywhere on the planet: within the bulk crust, lava outflows and the dust oxidized by chemical reactions with the Martian atmosphere, causing the surface to ‘rust’ slowly over billions of years, giving Mars its distinctive red hue.

The map showing hydrated minerals includes detections made by both ESA’s Mars Express and by NASA’s Mars Reconnaissance Orbiter.

Video credit: Hydrated mineral map: ESA/CNES/CNRS/IAS/Université Paris-Sud, Orsay; NASA/JPL/JHUAPL; Olivine, pyroxone, ferric dust & dust maps: ESA/CNES/CNRS/IAS/Université Paris-Sud, Orsay Orsay; Video production: ESA.