Liquid water could be lurking beneath the southern polar cap on Mars, according to new evidence reported in Nature Astronomy.
Dark streaks and other surface patterns on the slopes of Mars suggest that the unforgiving world of dust may have once supported lakes and oceans billions of years ago. The loss of its atmosphere is believed to have caused this surface liquid to be stripped away, leaving Mars dry and barren. However, scientists believe there is still water on Mars, albeit trapped in icy deposits frozen in regions that are cold and dry.
Now, tantalizing data collected from past and present orbiting spacecraft suggests that liquid water may still be flowing on the red planet. An international team of astronomers led by the University of Cambridge examined detailed maps of Mars’ south pole ice cap produced by the laser altimeter instrument on NASA’s now-defunct Mars Global Surveyor satellite, according to a publication released on Thursday.
They found an anomaly on the surface of the ice cap where the ice has formed a “raised bank” and a nearby “topographic depression,” features 10-15 kilometers long that suggest liquid water flows beneath. Next, they ran a computer model simulating surface features for ice sheets with water flowing underneath and found that it produced similar structures found in the anomaly. The team believes Mars must still be geothermally active to generate the heat needed to melt the ice cap.
Earlier radar measurements from NASA’s Mars Express orbiter highlighted a particularly bright spot where an area beneath a chunk of ice in the same region was more reflective. Some astronomers thought the high reflectivity was a sign that there was liquid water beneath the ice cap. However, others believed that the same signal could be generated by other effects such as conductive ice or minerals in the crust.
This latest study provides further evidence of liquid water beyond the initial radar results. “The combination of the new topographic evidence, the results of our computer model, and the radar data makes it much more likely that at least one area of subglacial liquid water exists on Mars today, and that Mars must still be geothermally active to sustain the water.” under the ice cap liquid”, Professor Neil Arnold, first author of the paper and Associate Professor at the Scott Polar Research Institute, University of Cambridge, said.
Similar surface features exist on Earth. The rise and fall of ice has been observed over subglacial lakes, and the team believes the same patterns are found on Mars, meaning there is liquid water hiding beneath its ice caps. Although the evidence may seem promising, scientists have yet to find any confirmation of liquid water on the Red Planet.
Frances Butcher, co-author of the paper and a planetary scientist at the University of Sheffield in England, said the study narrows down the conditions Mars must have for water to exist, which scientists can search for.
“Liquid water is an essential part of life,” she said, “although it doesn’t necessarily mean there’s life on Mars. To be liquid in such cold temperatures, the water under the South Pole may have to be very salty. What.” would make it difficult for any microbial life to inhabit, however, there is hope that more habitable environments existed in the past when climates were less forgiving.” ®
https://www.theregister.com/2022/09/30/mars_water_study/ Scientists present new evidence of liquid water on Mars • The Register