Recent findings indicate that Mars currently holds water beneath the surface. At a depth of between 11.5 and 20 kilometers down, an immense aquifer was uncovered by the NASA probe Mars Insight Lander. The idea of life on Mars has just been reawakened.
Here on Earth, microbes that live not just kilometers, but kilometers and kilometers, deep underground, have been found in total darkness. In a community that comes together around the chemistry of reactions called chemosynthesis, a process that uses chemical reactions instead of light . Such life represents a tremendous diversity that could exist on Mars.
Mars’ harsh surface is no place for life as we know it but traces of underground water suggest that, beneath the surface, life might still exist. On Earth, ecosystems thrive far beneath the surface in intensely challenging environments where food is often scarce. If life once existed on Mars, it might still be eking out a living in these hidden sources of water.
Some intriguing clues include the presence of methane in Mars’ atmosphere that changes concentration depending on the season. On Earth, methane is a common byproduct of microorganisms, which argues for life on Mars. But there are many other non-biological sources of methane, so further investigation will be needed.
Missions to retrieve Martian rocks back to Earth, such as the NASA Mars Sample Return mission, will bring us even closer than ever before. Some of those samples might likely contain traces of life. At the same time, we could study features such as Mars’ mud volcanoes to search for signs of subsurface activity.
Life-hunting is a tricky business on the Red Planet, and we might have to wait a very long time before we get clear answers. If successful, the hunt could yield a priceless reward: the discovery of living things, or at least some ancient evidence of life on the Red Planet.
Work Cited:
- Sci-News Staff. “NASA’s InSight Lander Ready to Explore Mars’ Interior.” Sci-News.com, 27 Mar. 2015, https://www.sci.news/space/science-insight-mars-lander-02852.html.
- Marshall, Michael. “Could Alien Life Survive in Deep Lakes Below Mars’ Surface?” BBC Future, 21 Aug. 2024, https://www.bbc.com/future/article/20240821-could-alien-life-survive-in-deep-lakes-below-mars-surface.
