Using new data about the Martian crust collected by NASA’s InSight spacecraft, geophysicists from the University of California, San Diego and the University of California, Berkeley estimate that groundwater could cover the entire planet to a depth of one to two kilometers. Groundwater exists in tiny cracks and pores in rocks in the mid-crust, 11.5 to 20 kilometers below the surface.
A cross section of NASA’s InSight lander and the data it collected. Image courtesy of James Tuttle Keane / Aaron Rodriquez.
“Liquid water existed at least occasionally in Martian rivers, lakes, oceans, and aquifers during the Noachian and Hesperian periods more than 3 billion years ago,” said Dr Vashan Wright of the Scripps Institution of Oceanography at the University of California, San Diego, and his colleagues.
“During this time, Mars lost most of its atmosphere and therefore the ability to support liquid water on its surface for any sustained period of time.”
“Ancient surface water may have been incorporated into minerals, buried as ice, trapped as liquid in deep aquifers, or lost to space.”
For the study, Dr Wright and his colleagues used data collected by InSight during its four-year mission, which ends in 2022.
The lander collected information from the surface directly beneath it about variables such as the speed of Mars’ seismic waves, which allowed scientists to infer what materials exist beneath the surface.
The data was fed into a model based on mathematical theories of rock physics.
Based on this data, the researchers determined that the presence of liquid water in the Earth’s crust was the most plausible explanation.
“If we prove that there is a large reservoir of liquid water, it could give us insight into what the climate was or could be like at that time,” said Professor Michael Manga of the University of California, Berkeley.
“And water is essential for life as we know it. I don’t see why underground reservoirs wouldn’t be habitable environments. On Earth they certainly are. There is life in deep mines, there is life at the bottom of the ocean.”
“We still don’t have evidence of life on Mars, but we’ve identified places that could, at least in principle, support life.”
“A wealth of evidence, including rivers, deltas, lake deposits, and hydrologically altered rocks, supports the hypothesis that water once flowed on the planet’s surface.”
“But that wet period ended more than 3 billion years ago, when Mars lost its atmosphere.”
“Planetary scientists on Earth have sent many probes and landers to Mars to learn what happened to the Martian water (water frozen in the Martian polar ice caps does not explain the whole story), when this happened, and whether life exists or ever existed on Mars,” the authors said.
“The new findings indicate that much of the water has seeped into the crust rather than escaping into space.”
“The new paper analyzes the deeper crust and concludes that the available data are best explained by a water-saturated mid-crust beneath the InSight location.”
“Assuming the crust is similar across the planet, this mid-crustal zone should contain more water than would have filled the hypothetical ancient Martian ocean.”
of Survey results Appears in Proceedings of the National Academy of Sciences.
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Vashan Wright others2024. Liquid water exists in the central crust of Mars. PNAS 121 (35): e2409983121; doi: 10.1073/pnas.2409983121
Source: www.sci.news
