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'
Changes Near Downhill End of a Martian GullyThis pair of images covers one of the hundreds of sites on Mars where researchers have repeatedly used the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter to study changes in gullies on slopes. Changes such as the ones visible in deposits near the lower end of this gully occur during winter and early spring on Mars, suggesting involvement of carbon-dioxide ice rather than liquid water.
The pair seen here shows the downhill portion of a gully that has been imaged several times. At left is the initial image and at right is one of the most recent views of the site. A lobate, rubbly flow (noted by the arrows) has been deposited near the mouth of the channel between the times of the two images. Further up the slope, the channel system has been modified by both erosion and deposition. Other images of the site pin down the timing of the changes more precisely, but it is easier to see the changes between these two views because the lighting is similar.
The area covered in these images is 164 yards (150 meters) wide. The location is on a crater rim at 37.7 degrees south latitude, 192.9 degrees east longitude.
Changes have now been visible in many gullies on Mars, and they show that these landforms are evolving rapidly. The timing of the changes is often in winter or early spring, suggesting that they are caused by the carbon-dioxide frost that forms in and around most gullies every year. Another example is shown at http://photojournal.jpl.nasa.gov/catalog/pia17958 .
The "before" image at left is a portion of May 30, 2007, HiRISE observation. The "after" image is part of a May 31, 2013, observation. Other image products from those observations are available at http://hirise.lpl.arizona.edu/ESP_032078_1420 and http://hirise.lpl.arizona.edu/ PSP_003939_1420 .
HiRISE is one of six instruments on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates HiRISE, 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 NASA's Science Mission Directorate, Washington.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona