Scientists have discovered a reservoir of liquid water on Mars - deep in the rocky outer crust of the planet.
The findings come from a new analysis of data from Nasa’s Mars Insight Lander, which touched down on the planet back in 2018.
The lander carried a seismometer, which recorded four years’ of vibrations - Mars quakes - from deep inside the Red Planet.
Analysing those quakes - and exactly how the planet moves - revealed “seismic signals” of liquid water.
IIRC the problem was the ambient temp that deep being too hot causing mechanical failures. It’s hard to dispose of waste heat when you have to pump it miles away.
You could probably drill much deeper into Mars before encountering that issue, though, since its molten rock is significantly deeper than Earth’s.