Researchers: It’s ‘Unlikely’ There’s Water- or Ice-Saturated Layers Below InSight Mars Lander

Did Mars ever support life? One clue might be quantifying just how much ice (and other minerals) are lurking just below the planet’s surface, a team of researchers argued this month. “If life exists on Mars, that is where it would be,” they said in a news release this week. “There is no liquid water on the surface,” but in a contrary scenario, “subsurface life would be protected from radiation.”

Locating ice and minerals has another benefit too, they write in the journal Geophysical Research Letters: to “prepare for human exploration.” And fortunately, there’s a tool on the InSight lander (which touched down in 2018) that can help estimate the velocity of seismic waves inside the geological crust of Mars — velocities which change depending on which rock types are present, and which materials are filling pores within rocks (which could be ice, water, gas, or other mineral cements).

That’s the good news. But after running computer models of applied rock physics thousands and thousands of times, the researchers believe it’s unlikely that there’s any layers saturated with water (or ice) in the top 300 meters (1,000 feet) of the crust of Mars. “Model results confirm that the upper 300 meters of Mars beneath InSight is most likely composed of sediments and fractured basalts.”

The researchers reached a discouraging conclusion, reports Space.com “The chances of finding Martian life appear poor at in the vicinity of NASA’s InSight lander.”
The subsurface around the landing zone — an equatorial site chosen especially for its flat terrain and good marsquake potential — appears loose and porous, with few ice grains in between gaps in the crust, researchers said…. The equatorial region where InSight is working, in theory, should be able to host subsurface water, as conditions are cold enough even there for water to freeze. But the new finding is challenging scientists’ assumptions about possible ice or liquid water beneath the subsurface near InSight, whose job is to probe beneath the surface.

While images from the surface have suggested there might be sedimentary rock and lava flows beneath InSight, researchers’ models have uncertainties about porosity and mineral content. InSight is helping to fill in some of those gaps, and its new data suggests that “uncemented material” largely fills in the region blow the lander. That suggests little water is present, although more data needs to be collected.

It’s unclear how representative the InSight data is of the Martian subsurface in general, but more information may come courtesy of future missions. NASA is considering a Mars Life Explorer that would drill 6 feet (2 meters) below the surface to search for possible habitable conditions. Additionally, a proposed Mars Ice Mapper Mission could search for possible water reservoirs for human missions.

And of course, as the researchers point out in their announcement, “big ice sheets and frozen ground ice remain at the Martian poles.”

Read more of this story at Slashdot.