for National Geographic News
Evidence has been found that liquid water is flowing on Mars, NASA scientists announced today.
"You've heard of a smoking gunthis the squirting gun," said Kenneth Edgett of NASA contract firm Malin Space Science Systems in San Diego, California.
The unexpected find emerged from some 240,000 images taken by the long-orbiting Mars Global Surveyor spacecraft.
Images taken of the same areas over time showed investigators that liquid water likely flowed through gullies in Martian craters during the past seven years.
Telltale deposits of debris suggest that sediments were washed downhill by occasional liquid flows.
"The shapes of these deposits are what you would expect to see if the material were carried by flowing water," said Michael Malin, president and chief scientist at Malin Space Science Systems. The firm designed the camera used on the Mars Global Surveyor.
"They have fingerlike branches at the downhill end, and [the deposits] easily diverted around small obstacles."
"It could be acidic water, it could be briny water, it could carry lots of sediment or be slushy, but [it appears that] water is involved," Edgett added.
Malin, Edgett, and colleagues announced the discovery this afternoon at NASA headquarters in Washington, D.C.
Their research is also reported in the current issue of Science.
Water's Origin Remains a Mystery
Scientists have long studied Martian surface features, like ravines, which suggest that liquid water flowed on ancient Mars.
SOURCES AND RELATED WEB SITES