LARGEST CARBONITE-RICH DEPOSIT ON MARS

FROM:  NASA
This view combines information from two instruments on NASA's Mars Reconnaissance Orbiter to map color-coded composition over the shape of the ground in a small portion of the Nili Fossae plains region of Mars' northern hemisphere.

This site is part of the largest known carbonate-rich deposit on Mars. In the color coding used for this map, green indicates a carbonate-rich composition, brown indicates olivine-rich sands, and purple indicates basaltic composition.

Carbon dioxide from the atmosphere on early Mars reacted with surface rocks to form carbonate, thinning the atmosphere by sequestering the carbon in the rocks.

An analysis of the amount of carbon contained in Nili Fossae plains estimated the total at no more than twice the amount of carbon in the modern atmosphere of Mars, which is mostly carbon dioxide. That is much more than in all other known carbonate on Mars, but far short of enough to explain how Mars could have had a thick enough atmosphere to keep surface water from freezing during a period when rivers were cutting extensive valley networks on the Red Planet. Other possible explanations for the change from an era with rivers to dry modern Mars are being investigated.

This image covers an area approximately 1.4 miles (2.3 kilometers) wide.  A scale bar indicates 500 meters (1,640 feet).  The full extent of the carbonate-containing deposit in the region is at least as large as Delaware and perhaps as large as Arizona.

The color coding is from data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), in observation FRT0000C968 made on Sept. 19, 2008.  The base map showing land shapes is from the High Resolution Imaging Science Experiment (HiRISE) camera. It is one product from HiRISE observation ESP_010351_2020, made July 20, 2013. Other products from that observation are online at http://www.uahirise.org/ESP_032728_2020.

The Mars Reconnaissance Orbiter has been using CRISM, HiRISE and four other instruments to investigate Mars since 2006. The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, led the work to build the CRISM instrument and operates CRISM in coordination with an international team of researchers from universities, government and the private sector. HiRISE is operated by the University of Arizona, Tucson, and was built by Ball Aerospace & Technologies Corp., Boulder, Colorado.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it.

Image credit: NASA/JPL-Caltech/JHUAPL/Univ. of Arizona

AEOLIAN BEDFORMS ON MARS

FROM:  NASA 

Sandy landforms formed by the wind, or aeolian bedforms, are classified by the wavelength--or length--between crests. On Mars, we can observe four classes of bedforms (in order of increasing wavelengths): ripples, transverse aeolian ridges (known as TARs), dunes, and what are called “draa.” All of these are visible in this Juventae Chasma image. Ripples are the smallest bedforms (less than 20 meters) and can only be observed in high-resolution images commonly superposed on many surfaces. TARs are slightly larger bedforms (wavelengths approximately 20 to 70 meters), which are often light in tone relative to their surroundings. Dark-toned dunes (wavelengths 100 meters to 1 kilometer) are a common landform and many are active today. What geologists call “draa” is the highest-order bedform with largest wavelengths (greater than 1 kilometer), and is relatively uncommon on Mars. Here, this giant draa possesses steep faces or slip faces several hundreds of meters tall and has lower-order superposed bedforms, such as ripples and dunes. A bedform this size likely formed over thousands of Mars years, probably longer. This image was acquired by the HiRISE camera aboard NASA's Mars Reconnaissance Orbiter on Jan. 6, 2014. The University of Arizona, Tucson, operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for the NASA Science Mission Directorate, Washington. > More information and image products.  Image Credit-NASA-JPL-University of Arizona Caption: Matthew Chojnacki.

NASA'S CURIOSITY MARS ROVER LOOKS AT TARGET

FROM:   NASA 

This image from the Navigation Camera (Navcam) on NASA's Curiosity Mars rover shows a sandstone slab on which the rover team has selected a target, "Windjana," for close-up examination and possible drilling.  The target is on the approximately 2-foot-wide (60-centimeter-wide) rock seen in the right half of this view.  The Navcam's left-eye camera took this image during the 609th Martian day, or sol, of Curiosity's work on Mars (April 23, 2014). The rover's name is written on the covering for a portion of the robotic arm, here seen stowed at the front of the vehicle. The sandstone target's informal name comes from Windjana Gorge in Western Australia.  If this target meets criteria set by engineers and scientists, it could become the mission's third drilled rock and the first that is not mudstone. The rock is within a waypoint location called "the Kimberley," where sandstone outcrops with differing resistance to wind erosion result in a stair-step pattern of layers.  Windjana is within what the team calls the area's "middle unit," because it is intermediate between rocks that form buttes in the area and lower-lying rocks that show a pattern of striations. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover and the rover's Navcam.  NASA's Curiosity Mars Rover Inspects Site Image Credit-NASA-JPL-Caltech.