UT Geologist Helps Look For Signs of Water on Mars

KNOXVILLE – The Mars Odyssey spacecraft has begun sending pictures of the Martian surface back to Earth.

University of Tennessee geologist Dr. Harry McSween will help NASA analyze those pictures for signs that water once flowed on or near the surface.

McSween, a UT Distinguished Professor of Geological Sciences, helped the space agency build a thermal camera used on the Odyssey spacecraft.

McSween said the imaging system doesn’t look for water itself, but the remains of where water once might have flowed.

“It tells you what the minerals are on the planet’s surface and it allows you to make maps of the distribution of minerals,” McSween said. “It sees evidence of the past presence of water, for example, if there had been a hot spring on the surface, it would have made some altered minerals. But we won’t see water now.”

The Thermal Emission Imaging System, or THEMIS, combines both visible and thermal infrared images of the Martian surface, and McSween and other analysts will study the surface features for clues to the past presence of water on Mars.

McSween said there are two reasons why NASA is looking so closely for signs of water on Mars.

“The first reason is that it’s what we can see from orbit that might tell us something about Martian life, if it exists,” McSween said. “The other reason is that Mars is the only other planet besides Earth that seems to show evidence of having had liquid water on or near its surface in its geologic past.”

After Odyssey arrived at Mars last October, NASA administrator Dan Goldin said the spacecraft’s mission would help the space agency’s ultimate goal of getting people to Mars safely.

McSween said geologists such as himself would likely be among the first to go, but not until the trip can be made more safe for the travelers.

“If you’re going to send people, geologists are the logical people to send, if they’re actually going to do work on the surface,” McSween said. “But it’s going to be awhile, because it’s such a challenge to overcome the medical problems of being in space over a lengthy time in a low-gravity, high-radiation environment.”