New Evidence of Water on Mars

Orbital imagery shows ancient riverbeds and what appear to be dried lake beds, and rovers have identified minerals that typically form in watery environments. These discoveries suggest Mars, billions of years ago during the Noachian and Hesperian periods (4.1 billion to 3 billion years ago), experienced a warmer, wetter period billions of years ago before transforming into the arid planet we observe today. As Mars’ magnetic field faded, its atmosphere thinned, and most of the water on the surface disappeared. Some escaped to space, some froze in polar caps, and some were trapped in minerals.

Our recent study may provide a solution. By analysing seismic data collected from NASA’s InSight mission, we have detected that seismic waves slowed down in a layer situated between 5.4 and 8 kilometres below the surface. This phenomenon could indicate the presence of liquid water at those depths. These discoveries were made thanks to the two meteorite impacts in 2021 (S1000a and S1094b) and a marsquake in 2022 (S1222a). These events sent seismic waves through the crust.

The discovery of the potential for liquid water below the Martian surface to support life is significant. On Earth, scientists have discovered microorganisms thriving in deep underground aquifers, existing in extreme conditions without sunlight. If similar life forms once flourished on Mars, these subterranean water-rich areas could be ideal for preserving evidence of ancient Martian ecosystems. This raises an exciting question: Did Mars host microbial life billions of years ago, and could we still find remnants in these hidden aquifers?

Additionally, this finding could pave the way for new possibilities regarding future human missions to Mars. The water beneath the surface could be extracted for use by astronauts, providing drinking water, oxygen, or even fuel for rockets. The extensive resources hidden underground could enhance Mar's viability as a destination for long-term human exploration, especially as interest in missions to the planet continues to grow.