Oxia Palus Quadrangle - Other Craters

Other Craters

Impact craters generally have rims with ejecta around them; in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact. Sometimes craters display layers. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed onto the surface. Hence, craters can show what lies deep under the surface.

• Trouvelot Crater floor, as seen by HiRISE

• Central peak of Radau Crater, as seen by HiRISE

• Kipini Crater south rim, as seen by HiRISE. Scale bar is 500 meters long.

• Sagan Crater Central Peak Ring, as seen by HiRISE. Scale bar is 500 meters long.

• Curie Crater, as seen by HiRISE

• Close-up of layers in central mound of Curie Crater, as seen by HiRISE

• Tayray Crater, as seen by HiRISE

• Light toned rocks surrounded by dark material along wall of a crater, as seen by HiRISE under HiWish program. Click on image for a better view.

• Pedestal Crater and ridge in Oxia Palus quadrangle, as seen by HiRISE. Click on image to see detail of the edge of the pedestal crater. The flat-topped ridge near the top of the image was once a river that became inverted. The pedestal crater superposes the ridge, so it is younger.

• Pedestal craters form when the ejecta from impacts protect the underlying material from erosion. As a result of this process, craters appear perched above their surroundings.

• Drawing shows a later idea of how some pedestal craters form. In this way of thinking, an impacting projectile goes into an ice-rich layer--but no further. Heat and wind from the impact hardens the surface against erosion. This hardening can be accomplished by the melting of ice which produces a salt/mineral solution thereby cementing the surface.