Washington: US researchers have determined the surface temperature of early Mars for the first time, providing evidence consistent with a warmer and wetter Martian past.
By analysing carbonate minerals in a four-billion-year-old meteorite that originated near the surface of Mars, scientists at the California Institute of Technology determined that the minerals formed at about 18 degrees Celsius (64 degrees Fahrenheit).
“The thing that’s really cool is that 18 degrees is not particularly cold nor particularly hot,” said Woody Fischer, assistant professor of geobiology and coauthor of the paper. “It’s kind of a remarkable result.”
Knowing the temperature of Mars is crucial to understanding the planet’s history -- its past climate and whether it once had liquid water.
The Mars rovers and orbiting spacecraft have found ancient deltas, rivers, lakebeds, and mineral deposits, suggesting that water did indeed flow.
“There are all these ideas that have been developed about a warmer, wetter early Mars,” Fischer says. “But there’s precious little data that actually bears on it.” That is, until now.
The finding is just one data point -- but it’s the first and only one to date.
“It’s proof that early in the history of Mars, at least one place on the planet was capable of keeping an Earthlike climate for at least a few hours to a few days,” says John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry, and a coauthor of the paper.
The study has been published online in the Proceedings of the National Academy of Sciences.