While most of the new impact craters found on Mars by the Mars Global
Surveyor's Mars Orbiter Camera have dark ejecta patterns, a few of them
also have light-toned ejecta, indicating that the impacting meteorite
excavated to a depth where a light-toned material was present.
Figure A: The picture was acquired on Feb. 26, 2006. The single small
crater of about 22.6 meters (about 74 feet) in diameter is surrounded by
light and dark-toned ejecta. The crater occurs near 20.6 degrees north
latitude, 356.8 degrees west longitude, in Arabia Terra.
Figure B: This set of images shows how the impact site appeared to the
Mars Odyssey Thermal Emission Imaging System infrared instrument before
and after the impact. The white circle indicates the location of the
impact site. Both images are from the Thermal Emission Imaging System band
9 (approximately 12.6 micrometers wavelength); the first image was
obtained on June 30, 2002, the second on Oct. 5, 2003. In the 2003 image,
the impact site appears as a bright spot, because it was warmer than the
surroundings at the time the data were acquired.
Figure C: The final figure shows how the impact site appeared to the Mars
Global Surveyor Mars Orbiter wide-angle cameras. The first image shows the
site before the impact, on Aug. 31, 1999. The second shows the impact site
as it appeared on May 7, 2003.
Taken together, the Mars Odyssey and Mars Global Surveyor data indicate
that this impact occurred some time between June 30, 2002, and May 7,
2003.
The Mars Global Surveyor mission is managed for NASA's Office of Space
Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena,
Calif., a division of the California Institute of Technology, also in
Pasadena. Lockheed Martin Space Systems, Denver, developed and operates
the spacecraft. Malin Space Science Systems, San Diego, Calif., built and
operates the Mars Orbiter Camera.
For more information about images from the Mars Orbiter Camera, see
http://www.msss.com/mgs/moc/index.html.
