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Summer snow on the Red PlanetNew photos from the Mars Global Surveyor reveal snow on Mar's northern hemisphere |
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Space Science News home |
Summer snow on the Red PlanetNew photos from the Mars Global Surveyor reveal snow on Mar's northern hemisphere |
 Mar 25, 1999:
It may be summer in the northern hemisphere on Mars,
but the Mars Global Surveyor captured this
view of some persisting frost or snow on a
small crater.
These snow fields are so small that a human could walk across
one of them in a matter of minutes. In winter, which ended
8 months ago on Mars,
the entire scene shown here would be covered by frost.
Right: Recently, the Mars Orbiter Camera (MOC) passed over a relatively small impact crater located at latitude 68°N (on the Vastitas Borealis plain, north of Utopia Planitia) and took this picture. Bright areas are thought to be frost or snow remaining from the frigid Martian winter than ended in July 1998. Illumination is from the upper right. This image of Martian snow was only one of three new images from Mars Global Surveyor released yesterday. |
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Until recently the elliptical orbit of the Mars Global Surveyor spacecraft carried it close to the surface of the northern hemisphere, but relatively far from the surface of the southern hemisphere. Photographs of objects in the north have shown great detail for some time, but southern images were fuzzier because they were taken from a greater distance. Now that the orbit has been circularized, through aerobraking, it is possible to see both halves of Mars in great detail. Striking photographs of the southern hemisphere are now pouring in -- an example is the Alexey Tolstoy Crater, pictured below. |
Left: A striking, but unnamed crater
inside the larger 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 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 at 47.6°S latitude, 234.6°W longitude in eastern Promethei Terra. With high resolution pictures of the northern and southern hemispheres now available on a regular basis, scientists will be able to monitor the ebb and flow of Martian seasons as never before, and perhaps gain a new understanding of Martian water, snow, and frost. |
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Mars Global Surveyor Web Site
A steamy cover-up on the red planet -- New evidence for active volcanism on Mars. Feb. 18, 1999 NASA Space Science News Bugs of Fire -- Spacelab crystallizes a protein from a very weird, and surprisingly common, volcano-loving bug. Scientists hope to discover how these bugs can survive in such extreme conditions. Sept. 16, 1998 NASA Space Science News The Sands of Mars -- Oct. 29, 1998 NASA Space Science News New NASA images of the Martian North Pole -- Oct. 23, 1998 NASA Space Science News New images of volcanoes on Mars and Io -- Oct. 14, 1998 NASA Space Science News The Planetary PhotoJournal -- the latest images from around the solar system JPL Press Release on Martian Sand Dunes Mars Global Surveyor Animations More NASA Space Science News |
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