By Chris Skeldon 
Water exists on Mars, according to a team of geophysicists, and not just as ice at the poles or vapor in the atmosphere. Scientists have found evidence of liquid water deep within the planet’s outer crust, based on an analysis of data provided by astronomers Mars Insight Lander From NASA.
Studies conducted through seismic activity
Specifically, they analyzed four years of ground motion recorded by the rover’s seismometer. By analyzing seismic velocities, or how fast seismic waves travel across the planet, they were able to determine the material through which the waves traveled. What they discovered was that Mars’ middle crust had cracked into igneous rocks saturated with liquid water.
One of the scientists involved in the study, Professor Michael Manga, from the University of California, Berkeley, told the BBC that they applied the same techniques used to “prospect for water on Earth, or to search for oil and gas”. He said his group’s findings could answer the question of where all the water went on Mars, where features on the planet’s surface show it had lakes and rivers around three billion years ago.
Although there is a theory that most of this water was lost to space, scientists have questioned this idea in recent years. A study from the California Institute of Technology and NASA’s Jet Propulsion Laboratory, published in 2021, found data suggesting that most of this water is still trapped in the planet’s crust.
The scientists involved in the new study, published in PNAS, were only able to analyse seismic velocity data collected under the lander. However, they believe similar underground water reservoirs exist all over the planet, and estimate that there is enough liquid water beneath the surface to form a half-kilometre-deep layer on Mars. “Most of our water is underground and there is no reason why that shouldn’t be the case on Mars as well,” Manga told the BBC.