Mars may still be home to oceanic quantities of liquid water, according to a recent paper published by the National Science Review.
Titled “Seismic evidence of liquid water at the base of Mars’ upper crust”, the paper [PDF] notes that liquid water once flowed freely on the surface of Mars before the planet’s magnetic field faded, its atmosphere thinned, and it became the dry and frozen hellscape we know today.
The paper’s authors – from China’s Academy of Sciences, the Australian National University, and the University of Milano-Bicocca – note the generally accepted theory that Mars’ water either evaporated into space or was somehow stored in the planet’s crust but worry there’s little evidence to help us understand how much water may remain.
They think they found that evidence in data gathered by the Mars InSight, the sadly defunct lander that studied the Red Planet’s interior, when it recorded the impact of two meteorite impacts in 2021 and a 2022 Marsquake.
Those incidents produced seismic waves that slowed as they passed through a layer between 5.4 and 8 kilometers below the surface.
The authors cite studies on how quickly seismic waves travel through porous rocks, plus research on how such waves behave as they pass through layers in Earth’s crust and conclude that Mars is home to a “water-soaked layer 5.4 to 8 kilometers deep.”
In a summary of the paper, Australian and Chinese researchers characterize the that layer as “most likely highly porous rock filled with liquid water, like a saturated sponge” and akin to Earth’s aquifers. The paper estimates the porous rocks contain enough water to cover Mars in a global ocean 520–780m deep.
If that sounds like a familiar theory, that may be because other researchers have used data from Mars InSight to conclude that Mars holds enough water to coat the planet in an ocean one or two kilometers deep.
The study hypothesized that the water is 11.5 to 20 km below the Martian surface.
As we pointed out when covering that finding, humans have only managed to dig 12km into our own planet and that took 20 long years of frustrating toil. Getting to Mars’ water could be even harder, even if it’s at just 5.4 km down as suggested in the new study, given the hellish environment and absence of local hardware stores. ®
