August 15, 2011
The channels on Mars widely supposed to have been created by flowing water have a completely different origin, says a Texas Tech University professor.
David Leverington says that an examination of , an associate professor in the Department of high-resolution photographs and mineralogical data shows that the largest 'ancient riverbeds' on Mars most likely were created not by water, but by massive, fast-moving, low-viscosity lava flows.
"Many scientists realize there are issues with aqueous interpretations of these channels," he says.
"They recognize that if these systems formed by giant subsurface flows of water, there would need to have been extraordinarily high ground permeability, up to a million or more times greater than what we’d expect for the crust of the Earth, just to allow sufficient amounts of water to make it to the outflow locations and erupt to the surface."
While water exists on the planet, most of it appears to be trapped at the poles and at higher latitudes in the form of ice. And, according to Leverington, it's unlikely that there's enough water elsewhere on the planet to have created the channels.