The Earth's deepest living organisms may hold clues to alien life on Mars

To understand what life might look like deep beneath the surface of Mars, scientists are looking at some of the oldest and most resilient organisms here on Earth. Even though Mars appears dry and barren on the surface, recent findings suggest there's a massive reservoir of liquid water buried deep in its crust, possibly hiding a whole different world beneath the red planet's surface.

Researchers from NASA's Mars Insight Lander have detected seismic waves that suggest layers of wet rock exist between 11.5 and 20 kilometers down. This discovery opens up the intriguing possibility that, if life exists on Mars, it could be thriving underground, just like many forms of life deep beneath Earth's surface.

Here on Earth, life has been found in some of the most extreme environments, far below the surface. For over 30 years, biologists have been uncovering evidence of life in deep-sea sediments, rock layers, and even within solid rock itself. Most of these underground dwellers are microorganisms like bacteria and archaea—some of the oldest forms of life on our planet. These organisms don't rely on sunlight for energy but instead use chemosynthesis, drawing energy from chemical reactions with the surrounding rocks and water. This kind of life, which can survive in total darkness and extreme conditions, could be the key to understanding what life might look like on Mars.

If Martian microbes exist, they might resemble these Earthly counterparts, clinging to life deep underground despite harsh conditions and limited nutrients. There’s even a chance that the methane plumes observed on Mars could be linked to these potential underground microorganisms, though there are other non-biological explanations as well.

The challenge now is figuring out how to explore these potential habitats on Mars. Drilling deep enough to reach these underground reservoirs would be a monumental task, especially on a planet as inhospitable as Mars. But if life was able to start on Mars, it might still be hanging on deep below the surface, waiting for us to find it.

For more insights, check out BBC website.