Deep under the ice of the Martian South Pole researchers have discovered signs of a hidden lake that could hold liquid water year-round, a crucial condition needed for life to develop.
An advanced satellite radar has found a massive anomaly—a 12-mile-long lake that researchers believe must be at least a meter thick. Previous discoveries on Mars have indicated liquid water that existed only seasonally.
“This is the first potential habitat,” said researcher
at the Italian National Institute for Astrophysics. “We don’t know it is inhabited, but if you’re looking for life on Mars, this is one of the prime places to look.”
Dr. Orosei and an international team of researchers probed through to the bottom of about a mile of ice on the planet’s south pole using a radar aboard the Mars Express Satellite, a European Space Agency mission. The Italy-based researchers published in Science on Wednesday the results of four years of radar readings. The lake, they say, was found because it produces different radar readings than the surrounding ice and bedrock.
“If the result can be confirmed, it would be the largest known occurrence of present-day liquid water on Mars,” said
at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who is the U.S. leader on the joint U.S.-Italy project that developed the radar system.
The technology used to find the lake has been pointed toward our own planet where it has effectively identified vast lakes under the ice in Antarctica.
But the indirect nature of the observation leaves the Mars data open to alternate interpretations. The lake could turn out to be frozen carbon dioxide, or dry ice.
The search for water on Mars has seen numerous false leads, including gullies more likely to have been caused by frozen carbon dioxide and ridges more likely to have been caused by sand than by water.
planetary geologist at the Applied Physics Laboratory at Johns Hopkins University, who wasn’t involved in the study, said more research is needed to ensure nothing about the unique environment of Mars could interfere with the results.
“Mars, as an alien world, can surprise us in operating in ways very different from how Earth operates,” Dr. Murchie said. “We need to keep an open mind to other explanations.”
Dr. Orosei said that the team examined other possible explanations. They concluded that the lake isn’t carbon dioxide and that the possibility it is metal is too unlikely, he said.
The researchers also faced the challenge of explaining why the water they found isn’t frozen. The temperature under the ice cap is too low for pure water to exist as a liquid, so the researchers propose the water is kept from freezing the same way ocean water is on Earth—by salt, in this case, perchlorate salt from surrounding soil.
“There is certainly water available in the ice cap, but the mystery is whether the temperature and the composition are right to maintain melting,” Dr. Plaut said.
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