Hidden underground water on Mars offers hope for life

Scientists have discovered evidence of a vast underground reservoir of liquid water using seismic studies of Mars' interior. This discovery suggests the presence of a place on the Red Planet that could potentially support life. Unfortunately, it is not easily accessible.

Data gathered by NASA's InSight lander suggest that beneath the surface of Mars, there is such a large amount of water that it could cover the entire planet with an ocean between 0.6 and 1.2 miles deep. Although this is good news for those interested in the fate of water on the planet after its oceans disappeared over 3 billion years ago, the discovered reservoir won't be very useful for future Martian colonies.

The water is hidden in microscopic cracks and pores in rock in Mars's middle crust at a depth of between 7 and 12.4 miles below the surface. Even on Earth, drilling a hole a mile deep is a major challenge. On the Red Planet, such tasks are even more difficult. However, the discovery points to another promising site for searching for life on Mars if access to this reservoir can be obtained. Its existence helps answer questions about the planet's geological history.

Vashan Wright from the University of California, San Diego, author of the study described in "Proceedings of the National Academy of Sciences," explains, "Understanding the Martian water cycle is critical for understanding the evolution of the climate, surface, and interior." He adds, "a useful starting point is to identify where water is and how much is there."

Scientists used a mathematical rock physics model, identical to Earth models, to map underground water reservoirs and oil deposits. This allowed them to infer that the seismic data from InSight is best explained by assuming the existence of a deep layer of fractured magmatic rock saturated with liquid water. Magmatic rocks are cooled hot magma, similar to the granite of the Sierra Nevada.

Prof. Michael Manga, one of the scientists, says, "Establishing that there is a big reservoir of liquid water provides some window into what the climate was like or could be like." He adds, "And water is necessary for life as we know it. I don’t see why (the underground reservoir) is not a habitable environment. It’s certainly true on Earth — deep, deep mines host life, the bottom of the ocean hosts life. We haven’t found any evidence for life on Mars, but at least we have identified a place that should, in principle, be able to sustain life."

According to scientists, various formations—river channels, deltas, lake deposits, and water-altered rocks—support the hypothesis that water once flowed on the planet's surface. However, this wet period ended over 3 billion years ago after Mars lost its atmosphere. Many probes and landers have been sent to the planet to check what happened to the water. The polar ice cannot explain everything. It is also unknown whether life exists or exists on the planet. New discoveries suggest that most of the water didn't escape into space but seeped into the crust.

NASA's InSight lander reached the surface of Mars on November 26, 2018. It is an acronym for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport. Its main task was to study the interior of the Red Planet, including monitoring seismic activity. During its mission, it detected over 1,300 "Marsquakes," providing scientists with valuable data on the planet's structure. Over 1,200 mission days, InSight encountered extreme environmental conditions that caused a massive dust buildup on its solar panels. This dust buildup prevented sufficient power generation, ultimately forcing the lander to end its mission.

One of InSight's most important discoveries was detecting the largest recorded earthquake on Mars. On May 4, 2022, an earthquake with a magnitude of 4.7 on the Richter scale was recorded. This event provided valuable information on the planet's seismic activity, indicating that Mars also experiences tectonic movements despite the lack of plate tectonics known from Earth. The InSight mission significantly advanced scientists' understanding of geological processes on Mars. The data it collected will be fundamental for future manned missions to the Red Planet, helping to plan landings and operations on its surface.