Two years ago, astronomers reported the discovery of a large lake of brackish water under ice at the South Pole of Mars, a discovery that was met with excitement and some skepticism. Now, researchers say they have confirmed the lake’s existence – and three more have been discovered.
Search, reported September 28 in Nature Astronomy1, Was built using the European Space Agency’s (ESA) Mardar Express spacecraft’s orbiting radar data. This is after the discovery of the only sub-surface lake In the same area In 2018 – If, it is confirmed, the liquid water discovered on the red planet will be the first body and a possible habitat of life. But the research was based on only 29 observations made from 2012 to 2015, and many researchers said they needed more evidence to support the claim. The latest study used a large data set that included 134 monitors between 2012 and 2019.
“We identified the same body of water, but we also found three more bodies of water around each other,” says Elena Patinelli, a home scientist at the University of Rome, who co-authored the paper. “It’s a complex system.”
The team called Mars Advanced Radar for Subsurface and Inosphere Sounding (MARSIS) to investigate the planet’s south polar region, using a radar device on the Mars Express to investigate the planet’s south polar region. Mars sends radio waves that emit layers of matter on the planet’s surface and sub-surface. The way the signal is reflected on the back indicates the type of material that is present in a particular place – for example rock, ice or water. One such method is used to identify the subcontinental glaciers on Earth. The team detected some areas of high reflection that they said showed more than a kilometer of Martian liquid water bodies trapped in the ice.
These lakes cover an area of about 75,000 square kilometers – an area of about one-fifth of Germany. The largest, the central lake, covers a distance of 30 kilometers, and is surrounded by three smaller lakes, each a few kilometers wide.
On the surface of Mars, low pressure makes liquid water impossible as a result of the Earth’s considerable lack of atmosphere. But scientists have long thought that water could be trapped beneath the surface of Mars, perhaps the remnants of the earth when there were oceans and lakes on Earth billions of years ago. If such reserves exist, they could potentially be habitable for life on Mars. On Earth, animals are able to live in sub-lakes Places like Antarctica.
But the amount of salt present can cause problems. It is thought that any underground lakes on Mars must have the right amount of salt to keep the water liquid. Although there may be some heat from the interior of Mars beneath its surface, it alone will not be enough to melt ice in water. “From a thermal point of view, it has to be salty,” says Petinelli.
John Presqu, an environmental scientist at Montana State University, says that seawater can help five times as much salt as seawater, but as you go about 20 times as far as seawater.
“There is not much active life in these glowing ponds in Antarctica,” says Prescu, whose group studies microbiology in icy environments. “They are just pickles. And this may be the case [on Mars]”
The existence of the Martian lakes themselves is also being debated. Since the 2018 discovery, researchers have raised concerns such as the lack of a suitable source of heat to convert ice into water. And while the latest research supports the 2018 observation and includes more data, not everyone is convinced that the identified areas are liquid water.
“If the luminous substance is really liquid water, I think it is more likely to represent some kind of dirt or grime,” says Mike Sori, a home geophysicist at Purdue University in West Lafayette, Indiana. .
Jack Holt, a home scientist at the University of Arizona who thinks the latest figures are accurate, is not sure about the explanation. “I don’t think there are lakes,” says Holt, who is on the science team for NASA’s Mars Reconnaissance Or Rabbit (MRO) and Mars Shallow Radar Sound (Shard). “There’s not enough heat flow to support Brian, even under the ice cap.”
A Chinese mission to Mars could offer a way to investigate the claims. The Tiananmen-1 mission Will enter orbit in February 2021, and with a rover mounted on the surface, the bit Rabbit will have a suite of scientific instruments. These include radar equipment that can be used to make such observations. David Flannery of the Queensland University of Technology says: “It has the same capabilities as Marsis and Sharad.
At the moment, the possibility that these lakes are remnants of Mars’ wet past is an interesting possibility. “There could be a lot of water on Mars,” says Patinelli. “And if there was water, there would be life.”