Mars Global Surveyor
Mars Orbiter Camera

Patterned Ground of the Martian Antarctic

MGS MOC Release No. MOC2-189, 15 November 1999


Remnant frost from the retreating south polar ice cap, trapped in cracks, enhances the visibility of polygonal patterns in this new picture of Malea Planum in the far southern regions of Mars. This scene, taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in October 1999 shows a relatively smooth portion of Mars (a plain) that is covered with polygons both at large and small scales. Smaller polygons are mostly found on the surfaces of old, mantled impact craters (e.g., top and lower center), while larger polygons are evident on the surfaces between the craters. (Note: The polygons are too small to see in the icon--click on it to see the full-resolution image and the polygons).

It is spring in the southern hemisphere of Mars, and the region shown here has recently emerged from beneath a winter coating of frost. Patches of frost (bright material) remain in the cracks that make up the edges of each polygon in the picture. The image covers a narrow strip of martian terrain only 1.5 km (0.9 mi) across at a resolution of 3 meters (10 ft) per pixel.

Polygons such as these are common in Earth's arctic and antarctic regions (see descriptions of Antarctic research and Antarctic pictures), and they usually indicate the presence of ice (i.e., frozen water) in the ground. Polygons form from the cycle of freezing and thawing of ground ice over the course of years, decades, and centuries. The fact that polygons are found on all surfaces in the Malea Planum scene shown here indicates that the ice is not too deeply buried because only a thin veneer (a few meters--or yards) of material appears to have covered the crater at the top of the scene.

Image credit: NASA/JPL/Malin Space Science Systems

Other MGS MOC views of arctic- and antarctic-style polygons:

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

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