Gusev Crater is an impact crater on Mars that looks as though a lake may have once filled it in the distant past.
Gusev Crater is about 145 km (90 miles) wide. It is located at 14.6° South latitude and 175.3° East longitude, along the boundary between Mars' southern highlands and its lowland northern plains. The crater is about 3,000 km (1,900 miles) southeast of the volcano Elysium Mons. Scientists believe the Gusev Crater was formed by the impact of an asteroid three to four billion years ago.
A valley named Ma'adim Vallis, which is connected to the south side of the crater, looks like it may have been a river channel that poured water into the crater in the past, forming a large lake. If the crater was indeed a lake, scientists expect it to contain layers of sediments as much as 915 meters (3,000 feet) thick that flowed in with the water. There may be other clues to a watery past within the crater, such as deposits of minerals, such as halite and gypsum, that form when water evaporates. Wet environments are the best places to look for life, which is why scientists are so eager to track down places on Mars that were once wet.
On the 3rd of January 2004, MER-A Spirit, one of the two Mars Exploration Rovers (MER) had landed within an 81 km by 12 km (50 by 7 miles) oval near the center of Gusev Crater. Once settled into its new "home", Spirit will begin its mission of exploring for geologic evidence of the presence of water in Gusev Crater's past.
||5th January 2004, 17:56:22
||Robert Stettner (Foxtrot)