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The red planet has become a little bluer, scientists announcing the discovery of what they believe to be a lake about 12 miles wide and hidden under 1.6 km of ice at the South Pole Of March.
Scientists have already offered much weaker evidence for such reservoirs, as well as strong evidence for smaller amounts of water on the planet. But the new discoveries will not fail to make a sensation.
"It's still exciting to talk about liquid water on Mars today," NASA researcher Ashwin Vasavada told Space.com for the Curiosity mission. However, he declined to say how confident he is in the claims of the study, because he's not an expert in the kind of radar imagery used by the company. 39; team. "It's exciting because of all the implications that this could have for the livability of Mars." [Geometry Helps Solve the Mystery of Mars’ Water]
And it is too early to say what exactly are these implications. Scientists have yet to confirm the discovery itself and understand precisely what features this water may have, which will require missions that have not yet been designed and even less launched.
Water under the Ice?
The new research builds on more than three decades of theorizing by scientists about the risks of infiltration. water.
This idea was first proposed by Steve Clifford, now a global scientist specializing in water on Mars at the Arizona-based Planetary Science Institute. , who was not involved in the new research. He was inspired by the studies of scientists on the lakes below the ice sheets of Antarctica and Greenland here on Earth, he told Space.com. These lakes are created when the heat of the interior of the planet melts glaciers in plates. He thought that a similar scenario could occur under the ice caps of Mars – we had no way of seeing under the ice.
New research has attempted to do this using radar data collected by an instrument called MARSIS, which uses radar pulses to study the ionosphere and the inner structure of the planet. It is orbiting the planet aboard Mars Express, a European spacecraft, since 2003.
Representation of an Mars Express artist in orbit with the spacecraft radar data on the left. The blue square represents the team's evidence for liquid water beneath the surface.
Credit: ESA, INAF. Graphical rendering by Davide Coero Borga, INAF Media
The radar signals that MARSIS produces rebound to Mars Express in different ways depending on what material they hit. And the team behind the new research said that the signals picked up by MARSIS on the south pole of Mars can only be explained by a large underground pool of liquid water.
"We discovered water on Mars," lead author Roberto Orosei -investigator on MARSIS and a scientist at the National Institute of Astrophysics in Italy, said in a video released with the newspaper. "MARSIS was able to detect echoes under the southern polar cap of Mars that were stronger than surface echoes. This condition on Earth only occurs when you observe subglacial waters like in Antarctica on places like Lake Vostok. " And although the team has evidence that for one place, they suspect that this is not the only subglacial lake (Antarctica caches about 400).
According to radar echoes, the lake does not exceed 12.5 miles (20 km) and is buried about one mile below the surface of the icecap. Scientists can not accurately determine the depth of the lake, but they confirmed that it was at least 1 meter deep. It must be rather salty, because the ice above is very clear and therefore quite cold – if there was pure water below this type of ice, it would be frozen, according to the researchers.
The team used half-year data to ensure that their analysis included several passages in the same region. They also looked at a few other scenarios that could have explained the data they saw, including a layer of ice of carbon dioxide hiding under the ice of water. But the researchers said that they left unsatisfied with these explanations.
Other scientists may not be in agreement. "I think it's a very, very persuasive argument, but it's not a conclusive or definitive argument," Clifford said. "There is always the possibility that conditions that we did not foresee exist at the base of the cap and are responsible for this bright reflection."
The research is described in an article published July 25 in the journal Science.
Representation of an artist of Mars Express on a plot of Planum Austral. the surface of the planet.
Source: USGS Astrogeology Science Center, Arizona State University, ESA, INAF. Graphic rendering by Davide Coero Borga, INAF Media
Life means water, but water does not mean life
If future studies confirm that the mysterious layer under ice is indeed water, attack the tank before they can make predictions about what discovery means for the possibility of life on Mars. [Curiosity Rover Finds Ancient ‘Building Blocks for Life’ on Mars]
"If you have liquid water and you consider its relevance to life, you must also go beyond the fact that it is liquid and ask at what temperature it is and if it can be used, "said Vasavada. "All liquid water is not equal in terms of life's ability to use it." In particular, he emphasized the high salt content that would be needed to keep liquid water at such low temperatures. This level could overwhelm even the saltiest life forms, he suggests.
Scientists on Earth drilled through glaciers to sample the water behind them and found microbial life. So, if there has ever been a life on Mars, this life could theoretically have survived, hidden in that lake or in similar lakes, Clifford suggested.
"There is no reason to expect that this will not continue until today," he said about any old microbial life on March. "The basement is a very, very stable environment compared to the surface of a planet, protected from impacts and protected from climate change."
Send an email to Meghan Bartels at [email protected] or follow her @meghanbartels . Follow us on @Spacedotcom Facebook and Google+. Original article on Space.com
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