Mars has a small South Polar cap of carbon dioxide ice. Although this cap persists year round, it is always changing: it has pits and mesas that in some places resemble a slice of Swiss cheese. The pits are expanding because the carbon dioxide is sublimating, but in other places new carbon dioxide deposits are building up on flat ground.
HiRISE monitors many areas of the cap to study these changes. Usually when we study changes, we can align the images with features that havenââ¬â¢t changed, but here that is difficult: nearly everything is different! By lining up the pattern of shallow pits on top of a mesa, which are not changing much, we can see the variations in the eight Mars years between observations (PSP_004992_0945 and this one). Some of the walls have retreated by more than 15 meters (about 50 feet).
The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. (The original image scale is 24.7 centimeters [9.7 inches] per pixel [with 1 x 1 binning]; objects on the order of 74 centimeters [29.1 inches] across are resolved.) North is up.
The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington.
A Crater in Scalloped Terrain
In the Wake of Ancient Lava Flows
The Tale of a Retreating Scarp
Slipping and Sliding in Echus Chaos
Mars Dust Storm in Relation to InSight, Curiosity and Perseverance
Landforms in Ares Vallis
Frosted Dunes in the Depths of Winter
Gullies and Boulder Tracks
InSight-Detected Impact in August 2021
InSight-Detected Impact in May 2020
News .
NASA to Host Briefing on InSight, Mars Reconnaissance Orbiter Findings
News .
Why NASA Is Trying to Crash Land on Mars
News .
NASA’s Curiosity Mars Rover Reaches Long-Awaited Salty Region
News .
NASA’s Mars Mission Shields Up for Tests
News .
NASA’s InSight Waits Out Dust Storm
Audio .
Episode 9: Before You Can Drive, First You Have to Fly
News .
NASA’s InSight ‘Hears’ Its First Meteoroid Impacts on Mars
News .
NASA’s Perseverance Rover Investigates Geologically Rich Mars Terrain
News .
NASA to Host Briefing on Perseverance Mars Rover Mission Operations
News .
NASA’s Perseverance Makes New Discoveries in Mars’ Jezero Crater
JPL is a federally funded research and development center managed for NASA by Caltech.