Flowing water on Mars hints at life
The data gathered by the Mars Reconnaissance Orbiter has given new focus to the hunt for life forms and scientists hope that in the coming years lab experiments and new space missions may shed more light on what they have seen.
"We have found repeated and predictable evidence suggesting water flowing on Mars," Michael Meyer, lead scientist for the Mars Exploration program, told reporters.
The US space agency said the orbiter circling Mars since 2006 had monitored numerous instances of what appeared to be water flows occurring in several locations during the Martian spring and summer.
"The best explanation we have for these observations so far is flow of briny water, although this study does not prove that," said Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory.
No liquid water has been found on Mars, though ice has been discovered at the poles. All life forms need water to survive, so the existence of a water source could point to a haven for primitive life.
"The next big question is to try to understand the origin and the source of these flows... (and) whether or not they may provide a conduit or a connectivity to a larger deeper brine pool or if in fact these fluids are just isolated patches or pockets."
It had identified 20 other possible sites of similar flows, he said.
McEwen cautioned that the water flows remained "circumstantial," and said scientists "lack that direct confirmation of water" from other instruments studying the planet, but hope it will be confirmed in future missions and lab experiments.
In any case, it does not appear that scientists are seeing anything akin to a gushing river on Mars, but more likely a subterranean movement.
Frozen water has been detected in some of Mars's higher latitudes, and other evidence has suggested that water interacted with the Martian surface throughout the planet's history.
Nasa has placed a renewed focus on Mars, with the 30-year space shuttle program now over and efforts under way to build a spacecraft capable of carrying humans to the red planet by 2030.
The largest US rover ever, built at a cost of $2.5 billion dollars, it is set to launch later this year and land in August 2012.
However, the area it will explore is far from the briny water slopes, so Curiosity is not expected to be able to confirm the latest findings.
