Story at a glance
- In 2018, scientists thought they had discovered liquid water at the South Pole of Mars.
- New research has now disputed that theory, arguing the temperature and pressure on Mars makes liquid water unlikely.
- Understanding if water has existed on Mars and if it can in the future could lead scientists to understanding the potential for sustainable life on the red planet.
Scientists have held on to the belief that water exists on Mars, but new research has found that may not be the case, as it was likely just an optical illusion.
Researchers published the details of a study that concluded liquid water previously detected at Mars’ ice-covered South pole is highly unlikely given the surface temperature and pressure on the Red Planet. That contradicts a theory that came about in 2018 after unusually bright basal reflections were detected at the South Pole Layered Deposits (SPLD) of Mars through the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) onboard the Mars Express spacecraft.
“Liquid water previously detected under Mars’ ice-covered south pole is probably just a dusty mirage,” said The University of Texas Institute for Geophysics (UTIG) in a statement.
Cyril Grima is the lead author of the new research and a planetary scientist at UTIG, and he described why the 2018 theory of water on Mars was unlikely.
“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 Grima.
Researchers now think that it was likely volcanic rock buried under ice when the 2018 discovery was made, which already seemed questionable to some as scientists calculated the unlikely conditions needed to keep water in a liquid state at Mars’ south pole.
Using radar mapping, Grima found that when imaginary ice sheets were placed across Mars, he noticed bright reflections just like those seen in 2018 on the South pole. This time however they were scattered across all latitudes, including in areas that matched the location of volcanic plains.
“I think the beauty of Grima’s finding is that while it knocks down the idea there might be liquid water under the planet’s south pole today, it also gives us really precise places to go look for evidence of ancient lakes and riverbeds and test hypotheses about the wider drying out of Mars’ climate over billions of years,” said Isaac Smith, a geophysicist at York University, in a statement.
NASA describes Mars as a rocky, cold and apparently lifeless planet. It’s home to the largest volcano in the solar system, the deepest canyon and crazy weather and temperature patterns.
The planet is known to have water locked up at its poles, but scientists haven’t figured out how much could be hiding beneath the surface. Understanding if water can exist on Mars could inform the possibility of life on the Red Planet
Scientists believe Mars does have ice water locked up at its poles, but they haven’t yet figured out how much water might be hiding below the planet’s surface. It’s a critical detail that could support scientists’ understanding of the possibility of life on Mars and inform the decision to send an astronaut there one day.
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