|Life in Space|
For most people, Mars conjures images of a cold, dead place with a dusty surface the color of paprika. But new photos—recently analyzed by Brown faculty and other researchers around the world—suggest that Mars is more lively than suspected.
The findings are stirring an old debate: Did life evolve on Mars, and, if so, is it flourishing today? Pictures taken by the Mars Express spacecraft found evidence of glacial movement and volcanic eruption in the last few million years—just yesterday in the planet’s 4.5 billion-year history. “Mars is dynamic,’’ said James Head ’69 PhD, a geology professor at Brown and a researcher on the mission. “Climate change and geological processes that cause evolution on Earth are actively occurring on Mars.”
Head and John Mustard ’90 PhD, an associate professor of geology, are part of an international team studying data from the unmanned orbiter launched in 2003 by the European Space Agency.
Head analyzed 3-D images from the craft, and Mustard observed the planet’s rocks, ice, and dust. Their re-search appeared in the journals Nature and Science, respectively.
Most scientists agree that Mars was wet and warm in its early days and that the water evaporated into the thin Martian atmosphere. Cold and bombarded by radiation, the planet could never sustain life as we know it. But some scientists wonder whether water—a key ingredient for life—remains beneath the surface.
One of the most striking photos Head studied shows a huge glacier near the planet’s equator. Does it still contain ice? Or is liquid water trapped beneath the glacier, where primitive microbes might thrive?
Other photos suggest that volcanoes may have erupted as recently as two million years ago. Researchers speculate that the heat from volcanic activity created a warm bath under the surface, making it hospitable to microorganisms.
Scientists also found traces of methane in the planet’s atmosphere, indicating either the presence of bacteria or simply a geothermal chemical reaction.
Using the orbiter’s infrared camera, or spectrometer, Mustard discovered minerals that had formed in water over long stretches of time, suggesting to the researchers that the conditions for life on Mars were present.
Mars Express will get back to work in May when it switches on a ground-penetrating radar instrument that should be able to detect water and ice several miles down. The results could be tantalizing. “Anything from a complete, eye-opener, ‘Wow!’ ” says Mustard, “to ‘That was pretty dull.’ That’s the beauty of exploration,” he says. “You don’t really know what’s going to happen.”
Elizabeth Rau is a Providence-based freelance writer.