June 8, 2010
More Evidence Of Seas Existing On Mars
Scientists have found further evidence that massive seas once existed on Mars.
A geological mapping project discovered sedimentary deposits in a region called Hellas Planitia, which suggests it was once a large sea.The 1,200 mile wide basin is a giant impact crater, the largest one on Mars.
The team says their data supports the theory that a lake existed there between 4.5 and 3.5 billion years ago.
Some scientists believe that conditions on Mars were more favorable for the evolution of life during this time than they were on Earth.
"This mapping makes geologic interpretations consistent with previous studies, and constrains the timing of these putative lakes to the early-middle Noachian period on Mars," Dr Leslie Bleamaster, research scientist at the Planetary Science Institute in Tucson, told BBC news.
The team says that fine-layered outcrops around the eastern rim of Hellas are likely to be sedimentary deposits.
They were formed from the erosion and transportion of rock and soil from the Martian highlands into a standing body of water.
The results support an earlier study of the western part of the Hellas basin.
Further research into this region could help provide clues about where this water went and how the Martian climate changed over geological history.
A number of instruments aboard NASA spacecrafts, including the Viking orbiter, Mars Global Surveyor and Mars Odyssey, helped the researchers map the area.
On the Net:
- Planetary Science Institute
- The new map and accompanying map pamphlet may be found at http://pubs.usgs.gov/sim/3096/