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
Ripple Movement on Sand Dune in Nili Patera, MarsBack-and-forth blinking of this two-image animation shows movement of ripples covering a sand dune on Mars. The images are part of a study published by Nature on May 9, 2012, reporting movement of Martian sand dunes at about the same flux (volume per time) as movement of dunes in Antarctica on Earth.
The before-and-after images were taken 15 weeks apart by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The scale bar is 85 meters (279 feet). The site is part of a dune field inside the summit caldera of Nili Patera, an ancient volcano, at 8.7 degrees north latitude, 67.3 degrees east longitude.
The images show a dark, rippled sand dune overlying bright-toned rock. They have been "orthorectified," that is, adjusted such that they appear as if viewed from directly overhead. They were then positionally tied together by registering fixed features on the bedrock seen in one image to the same features seen in the other. When the images are blinked back and forth, ripple motion during the intervening period of 105 days is clearly seen.
The first image, in which the side of the dune toward the bottom of the frame looks paler due to lighting effects, was taken on June 30, 2007. It is one image product of HiRISE observation PSP_004339_1890. Other image products from the same observation are at http://hirise.lpl.arizona.edu/PSP_004339_1890 . The "after" image was taken on Oct. 13, 2007. Other image products from the same HiRISE observation are at http://hirise.lpl.arizona.edu/PSP_005684_1890 .
HiRISE is one of six instruments on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates the orbiter's 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.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona/JHU-APL