Rock Types in Gale Crater, Annotated

This oblique view of the mound in Gale Crater shows several different rock types of interest to the Mars Science Laboratory mission.

The lower part of the mound consists of layers of rock in which orbiting instruments have detected the signatures of clay minerals and sulfate salts. Mars scientists have several important hypotheses about how these minerals reflect possible changes in the Martian environment, particularly changes in the amount of water on the surface of Mars. The Mars Science Laboratory rover, Curiosity, will use its full suite of instruments to study these minerals and how they formed to give us insights into these ancient Martian environments. These rocks are also a prime target in the search for organic molecules since these environments may have been habitable -- able to support microbial life. Scientists will study how organic molecules, if present, vary with mineralogical variations in the layers to understand how they formed and what influences their preservation.

A canyon (marked by the upper arrow) was cut through these layers after they formed. This canyon, much like the Grand Canyon in Arizona, exposes layers of rock representing tens or hundreds of millions of years of environmental change. Curiosity will be able to investigate these layers, gaining access to a long history of environmental change on the planet.

The canyon also contains sediment that was transported by the water that cut the canyon. This sediment interacted with the water at a time in which the environment may have been habitable. Thus, the rocks deposited at the mouth of the canyon (marked by the lower arrow) form a third target in the search for organic molecules.

The lighter colored rocks with a very different texture near the top of the image are also of interest. They appear to be very soft and easily eroded by the wind, unlike the rock layers lower in the mound. The composition of these rocks is entirely unknown; none of the orbiting instruments have detected distinctive signatures from them. If Curiosity travels as far up the mound as these rocks, we will be able to determine their composition and possibly their origin.

This three-dimensional perspective view was created using visible-light imaging by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter and the High Resolution Stereo Camera on the European Space Agency's Mars Express orbiter. Three-dimensional information was derived by stereo analysis of image pairs. The vertical dimension is not exaggerated. Color information is derived from color imaging of portions of the scene by the High Resolution Imaging Science Experiment camera.

The Mars Science Laboratory spacecraft is being prepared for launch during the period Nov. 25 to Dec. 18, 2011. In a prime mission lasting one Martian year -- nearly two Earth years -- after landing, researchers will use the rover's tools to study whether the landing region has had environmental conditions favorable for supporting microbial life and for preserving clues about whether life existed.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory and Mars Reconnaissance Orbiter projects for NASA's Science Mission Directorate in Washington.

The University of Arizona, Tucson, operates the High Resolution Science Imaging Experiment. The European Space Operations Centre in Darmstadt, Germany, operates the European Space Agency's Mars Express mission. The High Resolution Stereo Camera was developed by a group with leadership at the Freie Universitat Berlin.