Mars Global Surveyor
Mars Orbiter Camera

North Polar Cap Stratigraphy

MGS MOC Release No. MOC2-148, 19 July 1999

Stratigraphy is the study of layered sequences of rock and/or sedimentary materials. Of particular interest are the sequences of events that created the layered material, and the manner in which layers (or the materials in the layers) can be used to correlate events that occurred some distance apart from each other. With the 1.4 meters (5 feet) per pixel resolution of the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), it has now become possible to study some of the details in the thick layered deposits that comprise the martian polar caps.

Shown here are three different images taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles), and the latitude and longitude of each is indicated beneath the images. Despite the distance that separates these three samples of the polar cap, similar sequences of layers can be seen in each. More detailed studies of the north and south polar caps are underway by the MOC science team. For nearly three decades, these layers have been thought to consist of a mixture of ice and dust that record a history of the planet's most recent (i.e., the past few tens of millions of years) climate history. Each image in this picture is illuminated from the upper right, and the layers are expressed as series of rough-textured troughs and ridges.

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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