Misled by a Mars Mirage: Hope for Present-Day Martian Groundwater Dries Up:
Liquid water previously detected under Mars' ice-covered south pole is probably just a dusty mirage, according to a new study of the red planet led by researchers at The University of Texas at Austin.
Scientists in 2018 had thought they were looking at liquid water when they saw bright radar reflections under the polar cap. However, the new study published today (January 24, 2022) in the journal Geophysical Research Letters found that the reflections matched those of volcanic plains found all over the red planet's surface.
The researchers think their conclusion — volcanic rock buried under ice — is a more plausible explanation for the 2018 discovery, which was already in question after scientists calculated the unlikely conditions needed to keep water in a liquid state at Mars' cold, arid south pole.
"For water to be sustained this close to the surface, you need both a very salty environment and a strong, locally generated heat source, but that doesn't match what we know of this region," said the study's lead author, Cyril Grima, a planetary scientist at the University of Texas Institute for Geophysics (UTIG).
The south polar mirage dissolved when Grima added an imaginary global ice sheet across a radar map of Mars. The imaginary ice showed how Mars' terrains would appear when looked at through a mile of ice, allowing scientists to compare features across the entire planet with those under the polar cap.
Grima noticed bright reflections, just like those seen in the south pole but scattered across all latitudes. In as many as could be confirmed, they matched the location of volcanic plains.
Journal Reference:
C. Grima, J. Mouginot, W. Kofman, et al. The Basal Detectability of an Ice‐Covered Mars by MARSIS, Geophysical Research Letters (DOI: 10.1029/2021GL096518)
(Score: 0) by Anonymous Coward on Wednesday January 26 2022, @05:19AM
Fine women. I guess it's a desert so mirages are to be expected.
(Score: 1, Interesting) by Anonymous Coward on Wednesday January 26 2022, @08:53AM (4 children)
It never fails that you've got certain scientists constantly grasping at the slimmest of straws in hopes that Mars could support life or that it did in the past.
It is always proven false.
(Score: 1, Touché) by Anonymous Coward on Wednesday January 26 2022, @09:06AM (1 child)
This doesn't prove that it's lifeless or was always lifeless. There's still plenty of ice there, and there may be liquid water closer to the interior.
(Score: 0) by Anonymous Coward on Wednesday January 26 2022, @12:51PM
Nothing will *ever* be proof enough for some. The mindset is not scientific. It's like people who believe in haunted houses. Nothing can ever disprove it for them.
(Score: 4, Interesting) by Runaway1956 on Wednesday January 26 2022, @01:08PM (1 child)
As AC suggests, it has never been proven that Mars has never supported life. We haven't even proven that Mars is lifeless today. The only thing we can prove with certainty is that we have not discovered convincing evidence of life.
(Score: 0) by Anonymous Coward on Wednesday January 26 2022, @09:20PM
Nobody has proven that the Loch Ness monster DOESN'T exist, either. It has just never been found YET.
Still, I know which way I am betting.
(Score: 3, Insightful) by drussell on Wednesday January 26 2022, @12:16PM (1 child)
This really isn't surprising as the chances of actually finding liquid surface water was always incredibly remote...
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @05:19PM
While your point still stands, I am fairly certain that this was sub-surface water that was "detected" in 2018.
(Score: 2) by HammeredGlass on Wednesday January 26 2022, @04:20PM
There's no water over there. Trust us. That's our territory now as well. Don't go there.