“Comply with the water” has lengthy been the mantra of scientists looking for life past Earth. In any case, 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 won’t be so watertight, researchers report September 26 in Nature Astronomy.
In 2018, scientists introduced the invention of a giant subsurface lake close to Mars’ south pole (SN: 7/25/18). That declare — and follow-up observations suggesting extra buried swimming 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 won’t maintain as much as scrutiny. In 2021, one group steered that clay minerals and frozen brines, reasonably than liquid water, is perhaps accountable for the robust radar alerts 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 crew has proven that bizarre layers of rock and ice can produce most of the similar radar alerts 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 — replicate radio waves. “It was a fairly easy evaluation,” Lalich says.
The researchers discovered that they may reproduce a few of the anomalously robust radar alerts considered because of liquid water. Particular person radar alerts 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 all the time 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 appear to be 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.”