Is There Life in Liquid Water Now on Mars at a Depth of 5 to 10 Kilometers, and Could We Find It?

Sure-y, but when we get there we must dig anyway and we can go down.  anything e-se is unserious.

We can wait unti- we can produce gravity floors to provide one g for us.  Up to that we have to be tentative but still underground for habitation.  

We must estab-ish underground habitats for the entire human popu-atin on Earth.  After we mature Terra forming Terra. and humanity reaches 100,000,000,000.

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tIs There Life in Liquid Water Now on Mars at a Depth of 5 to 10 Kilometers, and Could We Find It?

The rose-colored rock (left), labeled Teghaza 001, is a meteorite from Mars (right) with an age of at least 4.1 billion years. It was discovered during 2022 in the Sahara Desert in Mali and its analysis was published in Science on October 29, 2026. (Image Credit: Darryl Pitt/Maine Mineral & Gem Museum/NASA/)

https://avi-loeb.medium.com/is-there-life-in-liquid-water-now-on-mars-at-a-depth-of-5-to-10-kilometers-and-could-we-find-it-983c783224a5

On Earth, deep subsurface life extends several kilometers down and may hold a comparable biomass to everything on the surface. Bacteria have been recovered from 5 kilometers deep in continental boreholes. The upper temperature limit for known life is about 122 degrees Celsius (°C).

Could the same be true of Mars? The Martian crust warms with depth at roughly 10–20 °C per kilometer. Starting from a mean surface temperature around −60 °C, the temperature ranges between about 0 and 120 °C at depths of 5 to 10 kilometers, potentially allowing life to survive in liquid water.

In 2018, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) on ESA’s Mars Express orbiter, detected a strongly reflective patch about 1.5 kilometers beneath the south polar cap. Its initial interpretation in terms of a subglacial lake of salty water was later replaced with the understanding that it is more likely a layered volcanic rock. It was also realized that perchlorate salts found by NASA’s Phoenix and Curiosity robotic missions, can pull water vapor from the air and form liquid films at night, a process Curiosity has indirectly detected. These are thin, briny, and fleeting layers, not an aquifer.

However, in 2024 the robotic NASA lander on Mars InSight, measured seismic velocities which revealed mid-crust beneath the lander, about 11–20 kilometers down, which is best explained by fractured rock saturated with liquid water. If that holds globally, the reservoir would be enough to cover Mars with a water depth of 1–2 kilometers, which would account for much of its missing ancient water in its hypothesized ancient lakes and oceans. The supporting evidence was presented in three papers here, here and here. The inference rests on one location and on model assumptions about rock porosity, so it is not conclusive without supporting data from more stations.

The deep Earth biosphere exists without sunlight or surface organics. Its microbes use hydrogen produced when water reacts with iron-rich minerals or when radiation from radioactivity splits water molecules in a process called radiolysis. The crust of Mars is basaltic, iron-rich, and radioactive enough that models find radiolysis alone could sustain microbial populations for billions of years. A 2021 study of Martian meteorites published here, concluded their mineralogy would generate enough hydrogen to support a deep biosphere on Mars comparable to Earth’s.

If life arose on the Martian surface during its wet period of 3.7–4 billion years ago, the deep crust is the one place it could have followed the water as the surface dried. Groundwater would have been connected to surface lakes then, so no migration across dry rock was necessary. In that case, the deep aquifer is not just habitable but is the one environment on Mars that has stayed habitable continuously.

In 2022, a rose-colored, 800-gram meteorite from Mars, labeled Teghaza 001, was discovered in the Sahara Desert in Mali. Its analysis was published here a few days ago and revealed that its age is at least 4.1 billion years old. This rock is a pristine piece of Mars’ primordial crust, providing a rare “Rosetta Stone” window into the Red Planet’s deep geological past. Microscopic analysis showed the rock’s minerals were heavily altered by liquid water about 4.1 billion years ago. This indicates that early Mars had a far more active subsurface water system than previously realized. Trapped hydrogen isotopes inside the rock show that even 4.1 billion years ago, Mars was already rapidly losing its lighter elements to space, hinting that its transition to a cold, dry world began early.

How feasible is it to drill Mars down to a depth of 5 to 10 kilometers in order to reveal whether it has life right now?

The deepest hole ever made is NASA’s Perseverance rover’s sampling cores at a few centimeters. InSight’s heat-flow probe, designed to reach 5 meters down, stalled at about 40 centimeters because the soil did not give it the friction it needed. ExoMars’ Rosalind Franklin rover, now scheduled for 2028, carries a 2-meter drill.

Terrestrial rigs that reach 5 kilometers weigh hundreds of tons and run on megawatts of power, with crews on site to change bits and handle casing. The Kola Superdeep Borehole took 19 years to reach 12 kilometers on Earth, with unlimited human attention and a surface base. Deep holes need to lift the rock debris out and to stop the walls from collapsing. On Earth the drilling mud is circulated by pumps and steel casing strings. Hard basalt erodes bits. Every bit change on Earth means pulling the entire string out and running it back in, which at 5 kilometers means days of work per change. A robot on Mars would have to do this thousands of times.

A simpler approach is to let geology do the digging. Impact craters, canyon walls, and fresh landslides expose material from kilometers down. The Martian Valles Marineris cliffs reach 7 kilometers, and some crater central peaks uplift rock from 5–10 kilometers. A rover at the base of such an exposure can sample deep crust without a drill. The downside is that the rock is dry and ancient by the time it is exposed, so it reveals the deep environment’s history, not whether water and life are there now. The challenge would be to sample deep fluids as soon as they surface. If the deep aquifer ever vents through fresh impacts, volcanic regions, or seepage, surface chemistry would carry its signature. A dedicated mission to a young volcanic or impact site, offers the best prospects for unraveling subsurface life on Mars.

The simplest way to confirm the aquifer is a network of seismic stations. A permanent human base with heavy equipment, local manufacturing of casing and bits, and years of continuous operation, could eventually accomplish the required drill and unravel not only water or life but also oil (as discussed here) that could power the local technological infrastructure.