spacetoday.net: Frozen sea may exist under Martian surface

Posted: Tue, Feb 22, 2005, 8:00 AM ET (1300 GMT)
Mars Express in orbit (ESA illustration)

A "frozen sea" of water ice may exist just below the Martian surface near the planet's equator, according to news reports. New Scientist reported Monday that scientists using images from ESA's Mars Express spacecraft have spotted what they describe as "raft-like" ground structures on the Martian surface about five degrees north of the equator. Scientists speculate these structures are blocks of water ice that were covered by layers of volcanic ash that prevented the ice from sublimating away. That ash layer, scientists speculate, could be as little as a few centimeters thick, making it easy for a future spacecraft mission to access the ice. Similar structures have been seen on the Martian surface before but have been attributed to lava, but scientists said that in this case the structures here are not consistent with lava. The research is scheduled to be presented at the Lunar and Planetary Sciences Conference next month, as well as to be published in the journal Nature. The MARSIS radar on Mars Express, to be deployed this spring, could confirm the discovery provided the water ice is not buried too far below the surface.