By Daniel Dunaief
After searching in 40 other places — albeit from millions of miles away — Deanne Rogers and her scientific colleagues from the U.S. and U.K. found what they were seeking. Using images beamed back to Earth, they found minerals on rocks that typically form in the presence of water.
The discovery, in the McLaughlin Crater on Mars, where deposits are probably 3.8 billion years old or older, is consistent with an expanding body of knowledge about the Red Planet.
“I almost expected we should see something like this,” explained Rogers, an assistant professor of geoscience at Stony Brook. “A lot of recent observations point to groundwater in the subsurface. There was a hint of water deep in the subsurface.”
Without channels going into or out of the basin, scientists suggested that the water likely came from under the ground.
Much of the water on Mars is likely a result of volcanic activity, although comet impacts may have also carried some. The water likely percolated through soil that is much more porous on Mars than it is on Earth. It likely collected several kilometers below the surface. The water may have come back up in deep basins, such as the McLaughlin Crater.
Indeed, there could still be water in the Martian crust.
If manned missions went to Mars, experts have suggested that the astronauts might need to find water on the planet to drink while they’re there and to restock their supplies for the long journey back to Earth.
Rogers suggested that astronauts probably wouldn’t be able to drill deep enough to get any groundwater. Some scientists, however, have been working on how to free the water trapped in the minerals on the rocks. By heating the rocks, astronauts might be able to release water. They could also go to high latitudes, where there is water ice within centimeters of the surface.
So far, the McLaughlin crater “is the only place where we find evidence of these minerals” together in a basin setting, Rogers offered. Some are covered in dust, which obstructs the scientists’ view, while others may never have had water upwell in that region.
The presence of water, even long ago, might suggest that conditions on Mars could have supported life. Those extraterrestrial organisms could have lived in the subsurface, where they might be sheltered from the harsh environment on the surface.
Despite the pervasive dust, Mars presents a clearer picture in some areas of geological processes than the Earth. Plate tectonics — the slow movement of the enormous landmasses on which the continents rest — on our planet muddy the waters of interpreting how the planet may have changed over its history.
Mars, however, does not have any such movement of tectonic plates. Additionally, the meteorites that slammed into its surface have helped reveal what is and was beneath the surface.
“It’s a lot easier to study craters on Mars because they are well preserved,” explained Rogers. “On Earth, they are buried under vegetation or erased from Earth’s surface” by the movement of the plates and by erosion or weathering.
Rogers explained that she has divided her research into analyzing data sent from orbiters and studying the properties of similar rocks and minerals that other researchers at Stony Brook have created.
“We can look at the spectra of altered samples to compare it to Martian data,” she explained. “We can confirm it in the lab.”
She also does some remote sensing of the moon and asteroids.
Rogers lives in Selden with Tim Glotch, who is also an associate professor in the same department (see July 17, 2012 issue), and their two preschool-age children.
Glotch, Rogers and a few other Stony Brook faculty are working on a multidisciplinary proposal, which is due in April, that considers the possibility of human exploration of the moon and asteroids. Glotch is the lead investigator, while Rogers and others have responsibilities specific to their expertise.
Their research is benefiting from a resurgence of interest in Mars, in part because of the newest rover, Curiosity.
Rogers said she hopes to continue to participate in research on Mars because “there are so many things left unexplored at this point.”