 |
The crater at the left is just a bit smaller than the Earth's most famous crater--Meteor Crater in Arizona. A dune field rests on the floor. Fine material seems to have covered any trace of layers on the walls.
This circle, which is scaled to the size of the pictutres on this page, respresents the size of the meteorite that struck Arizona to form Meteor Crater. It may very well be the comparative size of the body that produced the crater on the left. |
This picture and others on this page are approximetely 1 mile wide. They were all taken with the MOC on the Mars Global Surveyor.
The crater to the right is a
little bit bigger than Earth's Meteor crater. Dark gullies in the North wall may be due to rather recent flows of water.
|
 |
| |
MOC S11-01674 |
 |
The meteroite that created the crater at the left may have pentrated to a brigher layer of rocks, then threw the lighter material on top of the dark surface materials. |
 |
In contrast to the above scene, the meteroite that struck this area pentrated to a dark layer. The dark materials were then thrown out over the surface. By exploring close to craters, we can study rocks that lie deep beneath the surface without digging or drilling.
In the upper right of the picture there is a contact with a much rougher layer. |
| The crater at the right rests on a platform. Such craters are called pedestal craters. The pedestal is apparently ejected debris that protected the surface from subsequent erosion. The area around the pedestal has all been eroded away. These type of craters are common in the Northern hemisphere between 30 and 70 degrees. The grainy aspect of the surface is called patterned ground. Such ground is believed to be caused by the freezing of water in the ground. |
 |
 |
I call this the "brain crater" for the formation on the floor. It appears that this area has a thin light colored materal lying on top of a thin dark layer. Next there is a thick light layer than a thick dark layer at the lowest point in the crater. The "brain" at the bottom is probably light material blown into intersecting sand dunes. |
| This crater seems unusual with its bright bottom. The walls contain outcrops of rock, but most of the walls are just gray material.. |
 |
| A dark layer of rocks is apparent just beneath the brighter surface of the crater at the right. Impact craters are nature's way of showing us what lies under the surface. The wave-like forms right of the crater and on its floor are sand dunes. This crater is a little smaller than Earth's Meteor crater. |
 |
 |
The image on the right includes part of Maja Valles, a very large river valley. The MGS was directed to take a picture of a crater. |
 |
Here we see that the Northern wall of the crater of
the crater is broken up into a series of steps. It would
be quite a challenge to hike out of the crater, if you
landed on the floor. |
| On the right, craters are visible with odd deposits inside. The materials on the inside appear different than what is on the outside. Scientists believe that after the craters were formed they may have turned into lakes. The lakes built up deposits over time. Later, the whole region may have been covered over by other materials, perhaps ash from volcanoes. Finally, erosion may have removed top layers to show the craters with lake deposits. All this is quite possible because much of the Mars we see is billions of years old. There was plenty of time for all these events to occur. On earth, plate tectonics and eroision have made erased most of our oldest rocks. |
 |
 |
With the right lighting conditions, craters can be very
beautiful, as in the image at the right. Notice the rough
edges of the shadow that are due to the roughness
of the crater wall.
Last revised January 2007
To see more images click here.
Return to Home Page. |
