Remains of water once on the surface of Mars it may be hidden in a handful of small lakes below the South Pole of the Red Planet, and new research suggests there may be more.
For decades, researchers have suspected that water lurks beneath Mars’ polar ice caps, just as it does here on Earth. In 2018 scientists have found evidence of such a reservoir on the Red Planet – signs for a lake about 19 miles (19 kilometers) and hidden under about a mile (1.5 kilometers) of ice at the south pole of Mars.
At the time, researchers said studying the underground basin could give an idea of past and present chances. life on Mars. However, scientists had many more questions than answers about the origin, composition and longevity of this lake and its water.
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In the new study, to learn more about this hidden water, researchers used the MARSIS radar device aboard the European Space Agency. Mars Express a spacecraft to scan an area measuring 1
Scientists have confirmed the liquid nature of the previously observed lake, narrowing its size to about 20 by 30 miles. They can’t say how deep the lake stretches because MARSIS radio waves can’t penetrate salt water, study co-author Elena Pettinelli, a geophysicist at Roma Tre University in Rome, told Space.com.
In addition, Pettinelli and her colleagues have identified three other lakes measuring 10 by 10 km. Strips of dry rock separate these smaller sections of water from the main lake, scientists said.
Researchers suggest that these lakes are unusually salty. The high content of brine would keep their water liquid despite the extremely cold conditions at the base of the glaciers at the south pole of Mars, scientists note.
Although Martian polar ice may melt slightly due to warm noon temperatures, scientists do not believe that such processes are likely to have formed these lakes. Instead, scientists believe that this salt water could be the remains of a larger body of water that is now being lost from the surface, and could be millions or even billions of years old, Pettinelli said.
Scientists have considered the possibility that geothermal activity it may have melted polar ice to form underground lakes, but this explanation is plausible when there is only one such body of water. The formation of several lakes in this way may require a huge geothermal anomaly. “I don’t think it’s physically possible, given what we know,” Pettinelli said.
Instead, these lakes may have formed due to a warmer global climate in the past on Mars, Petinelli said. “It’s a complex system of water, not just a pond,” she said. “This suggests that the conditions that created these lakes may have been more prevalent in the region, that there may be other systems like this around.”
In general, if these lakes “are remnants of water that was once on the surface, it could certainly have been a good habitat to shelter life, extinct or alive,” Pettinelli said. But the ideal mission to study such potential life would be to dig 1.5km into the ice, which is not possible with available technology, she said. “However, maybe one day a mission to the Martian poles can take a sample from the surface there to see if we can find interesting information,” Pettinelli said.
In the future, scientists would like to look for similar networks of lakes elsewhere at the South Pole and perhaps at North Pole too, Petinelli said.
Scientists in detail their findings online today (September 28) in the journal Nature Astronomy.
Follow Charles K. Choi on Twitter @cqchoi. Follow us on Twitter @livescience and Facebook.