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“Comply with the water” has lengthy been the mantra of scientists looking for life past Earth. In spite of everything, the one recognized cradle of life within the cosmos is the watery planet we name dwelling. However now there’s extra proof suggesting {that a} potential discovery of liquid water on Mars might not be so watertight, researchers report September 26 in Nature Astronomy.
In 2018, scientists introduced the discovery of a large subsurface lake near Mars’ south pole (SN: 7/25/18). That declare — and follow-up observations suggesting additional buried pools of liquid water on the Purple Planet (SN: 9/28/20) — fueled pleasure about lastly discovering an extraterrestrial world probably conducive to life.
However researchers have since proposed that these discoveries may not maintain as much as scrutiny. In 2021, one group advised that clay minerals and frozen brines, moderately than liquid water, may be answerable for the sturdy radar indicators that researchers noticed (SN: 7/16/21). Spacecraft orbiting Mars beam radio waves towards the Purple Planet and measure the timing and depth of the mirrored waves to deduce what’s beneath the Martian floor.
And now one other workforce has proven that bizarre layers of rock and ice can produce most of the identical radar indicators beforehand attributed to water. Planetary scientist Dan Lalich of Cornell College and his colleagues calculated how flat layers of bedrock, water ice and carbon dioxide ice — all recognized to be plentiful on Mars — mirror radio waves. “It was a fairly easy evaluation,” Lalich says.
The researchers discovered that they might reproduce a few of the anomalously sturdy radar indicators considered because of liquid water. Particular person radar indicators from completely different layers of rock and ice add collectively when the layers are a sure thickness, Lalich says. That produces a stronger sign, which is then picked up by a spacecraft’s devices. However these devices can’t at all times inform the distinction between a radio wave coming from one layer and one which’s the results of a number of layers, he says. “They seem like one reflection to the radar.”
These outcomes don’t rule out liquid water on Mars, Lalich and his colleagues acknowledge. “That is simply saying that there are different choices,” he says.
The brand new discovering is “a believable situation,” says Aditya Khuller, a planetary scientist at Arizona State College in Tempe who was not concerned within the analysis. However till scientists get much more information from the Purple Planet, it’ll be troublesome to know whether or not liquid water really exists on Mars, Khuller says. “It’s essential to be open-minded at this level.”
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