01.06.2017 Earth and Its Moon, as Seen From Mars
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
Changes in Ripples on Martian Dunes in Nili PateraThree pairs of before and after images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter illustrate movement of ripples on dark sand dunes in the Nili Patera region of Mars.
The three images on the left are excerpts from a June 30, 2007, observation (late autumn at the site). The three on the right are of the same ground observed 15 weeks later, on Oct. 13, 2007 (winter at the site). Ripple crests discernable in the central portion of each image are diagrammed in the lower right portion of each image, with blue lines highlighting the largest changes. White scale bars in the bottom right of each of the six images are 20 meters (66 feet) long. North is toward the top.
A locator map at http://photojournal.jpl.nasa.gov/catalog/PIA12857 shows the context for the areas shown in these images. The inset box there labeled 3a-a' indicates the location of the top pair here. The boxes 3b-b' and 3c-c' indicate the locations of the middle and bottom pairs here, respectively. The site is field of dark sand dunes at 9 degrees north latitude, 67 degrees east longitude.
This comparison is part of a study of whether wind-shaped bedforms on Mars -- dunes and ripples -- are actively migrating in present-day atmospheric conditions. It is from a presentation by S. Silvestro, L.K. Fenton and D.A. Vaz at the 41st Lunar and Planetary Sciences Conference, March 2010, reporting that the bedforms at this Nili Patera site are actively migrating. The changes suggest that these dunes are not heavily cemented or crusted.
Other products from the June 30, 2007, HiRISE observation of this dune field are available at http://hirise.lpl.arizona.edu/PSP_004339_1890. Other products from Oct. 13, 2007, observation are available at http://hirise.lpl.arizona.edu/PSP_005684_1890.
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, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the spacecraft development and integration contractor for the project and built the spacecraft.
Image Credit: NASA/JPL-Caltech/University of Arizona/International Research School of Planetary Sciences