PIA07972: Four Mars Years of Change
 Target Name:  Mars
 Is a satellite of:  Sol (our sun)
 Mission:  Mars Global Surveyor (MGS)
 Spacecraft:  Mars Global Surveyor Orbiter
 Instrument:  Mars Orbiter Camera (MOC)
 Product Size:  537 x 1185 pixels (w x h)
 Produced By:  Malin Space Science Systems
 Producer ID:  MOC2-1100
 Full-Res TIFF:  PIA07972.tif (637.2 kB)
 Full-Res JPEG:  PIA07972.jpg (108.4 kB)

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Original Caption Released with Image:

23 May 2005
These two Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images were acquired a little more than four Mars years apart. One Mars year is about 687 Earth days long. The two images show a portion of the south polar cap, which is composed of frozen, layered, carbon dioxide. Each Mars year since MGS has been observing the planet, the mesas and buttes composed of carbon dioxide have gotten a little bit smaller, and the pits and holes have become a little bit wider. The scarps formed in frozen carbon dioxide in the south polar region are retreating at an average rate of about 3 meters per Mars year. The example shown here includes an image obtained in August 1999, and a more recent picture from April 2005. Arrow "1" points to a dramatic example of the changes that have occurred; in this case a mesa shrank to a small butte in just four martian years. Arrow "2" indicates pits that developed in the cap layer of a carbon dioxide mesa that eroded during the same interval. Acquired during early southern spring, both images are illuminated by sunlight from the upper left.

Image Credit:
NASA/JPL/Malin Space Science Systems

Image Addition Date:
2005-05-23