The circular, polar orbit of Mars Global Surveyor (MGS) achieved in early 1999 has begun to provide many opportunities to examine features in the martian southern hemisphere at high resolution. One of our favorite examples (thus far) is this picture of a small portion of the floor of Alexey Tolstoy Crater.
The top of the image shows a dark surface that is extremely rough and rocky. The rest of the image shows a brighter, smoother material. It appears that the bright material has been eroded back, exposing the lower, darker surface. The small crater that dominates this picture is only about 850 meters (930 yards) wide and has also been partly exhumed/exposed from beneath the bright, smooth material. Illumination is from the upper left.
Alexey (or Aleksey) Tolstoy Crater, in which the small unnamed crater seen in this picture occurs, was named by the International Astronomical Union in 1982 to honor the Soviet writer who died in 1945. It is one of only a few craters on Mars designated by both the first and last names of the honored person. The Alexey Tolstoy Crater has a diameter of 94 kilometers (58 miles) and is centered at 47.6°S latitude, 234.6°W longitude in eastern Promethei Terra.
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.