Map of Martian Thorium at Mid-Latitudes
This gamma ray spectrometer map of the mid-latitude region of Mars
is based on gamma-rays from the element thorium. Thorium is a
naturally radioactive element that exists in rocks and soils in extremely
small amounts. The region of highest thorium content, shown in red,
is found in the northern part of Acidalia Planitia (50 degrees latitude,
-30 degrees longitude). Areas of low thorium content, shown in blue,
are spread widely across the planet with significant low abundances
located to the north of Olympus Mons (near 55 degrees latitude,
-155 degrees longitude), to the east of the Tharsis volcanoes
(-10 degrees latitude, -80 degrees longitude) and to the south and
east of Elysium Mons (20 degrees latitude, 160 degrees longitude).
Contours of constant surface elevation are also shown. The long
continuous contour line running from east to west marks the
approximate separation of the younger lowlands in the north from
the older highlands in the south.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey
mission for NASA's Office of Space Science, Washington, D.C.
The gamma ray spectrometer was provided by the University of Arizona,
Tucson. Lockheed Martin Astronautics, Denver, Colo., is the prime
contractor for the project, and developed and built the orbiter.
Mission operations are conducted jointly from Lockheed Martin and
from JPL, a division of the California Institute of Technology in Pasadena.
Credit: NASA/JPL/University of Arizona