11.15.2016 Schiaparelli Impact Site on Mars, Stereo
11.03.2016 Schiaparelli Impact Site on Mars, in Color
03.30.2016 Erisa Hines
03.30.2016 Buzz Aldrin
03.21.2016 For a Decade Orbiting Mars: One Recent View
03.09.2016 For a Decade Orbiting Mars: One Recent View
03.09.2016 Mars Reconnaissance Orbiter By the Numbers
03.01.2016 MRO sees Frosty Spring Slopes
02.12.2016 Women in Science
02.10.2016 Wind at Work
11.16.2015 Change Observed in Martian Sand Dune
10.05.2015 'The Martian' Story's Ares 4 Landing Site
10.05.2015 The Ares 3 Landing Site (Figure A)
09.30.2015 Avalanche Ho!
06.29.2015 Mars Exploration Zone Layout Considerations
06.17.2015 Active High-Latitude Dune Gullies
06.03.2015 Crisp Crater in Sirenum Fossae
05.20.2015 Sedimentary Rock Layers on a Crater Floor
05.20.2015 Honey, I Shrunk the Mesas
05.11.2015 Icy Wonderland
05.04.2015 Diverse Orbits Around Mars
03.27.2015 South Pole Spiders
03.27.2015 A Smile a Day....
03.25.2015 Pitted Landforms in Southern Hellas Planitia
03.12.2015 Curiosity Heading Away from 'Pahrump Hills'
02.18.2015 Lava Flow Near the Base of Olympus Mons
02.09.2015 Yardangs in Arsinoes Chaos, Mars
02.04.2015 Curiosity Rover at 'Pahrump Hills'
01.22.2015 Frost on Crater Slope
01.16.2015 Components of Beagle 2 Flight System on Mars
12.03.2014 An Enigmatic Feature in Athabasca Lava Flows
12.02.2014 NASA's Journey to Mars
11.07.2014 Mars Orbiter Sizes Up Passing Comet
10.19.2014 Siding Spring Mars Spacecraft
10.01.2014 Dunes and Ripples in Nili Patera
09.11.2014 Curiosity Rover Planned Route
09.11.2014 Geological Transition
09.11.2014 Bands on the 'Murray Formation'
Pitting from Sublimation of Underlying Dry-Ice LayerThese images from orbit show an area near Mars' south pole where coalescing or elongated pits are interpreted as signs that an underlying deposit of frozen carbon dioxide, or "dry ice," has been shrinking by sublimation.
The image on the left covers an area about 5.2 kilometers (3.2 miles) across, near 87 degrees south latitude, 268 degrees east longitude. It was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. North is toward the lower left. The area indicated by the inscribed rectangle near the directional arrow is enlarged as the image on the right.
Observations by the Shallow Subsurface Radar (SHARAD) instrument on the same orbiter indicate a thick deposit of dry ice beneath the surface in this area. Sublimation of that dry ice may have caused the pitting. In the magnified image at right, a thin water-ice layer on the surface exhibits heavy and concentric fracturing that may be a response to continued sublimation of the underlying, radar-detected layer. The smoother surface in much of the lower portion of the right-hand image is a thinner coat of dry ice that formed over the water ice after the fracturing and that is part of what is know as the "residual cap."
These images are portions of HiRISE observation ESP_014342_0930, taken Aug. 18, 2009. Other image products from this observation are available at http://hirise.lpl.arizona.edu/ESP_014342_0930. HiRISE is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo.
SHARAD was provided by the Italian Space Agency. Its operations are led by Sapienza University of Rome, and its data are analyzed by a joint U.S.-Italian science team. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the spacecraft.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona