Indicators of Liquid Water Beneath Mars’ Surface Enhance Potential for Life
Recent research suggests the presence of “seismic discontinuities in the Martian crust,” which scientists believe may indicate the existence of liquid water beneath the surface of Mars. This discovery raises exciting possibilities about the existence of microbial life on the Red Planet. With a history that shares some similarities with Earth and its relatively close proximity to our planet, Mars has been a significant focus for astrobiology over the years.
The findings suggest that liquid water, an essential ingredient for life as we understand it, might still exist beneath Mars’ harsh and rocky exterior. This news has reignited discussions about the potential for microbial life to survive and thrive beneath the planet’s surface, where it could find the necessary conditions for survival despite the stark climate.
Ikuo Katayama, a planetary scientist from Hiroshima University and one of the study’s co-authors, highlighted the implications of liquid water on Mars by stating that its presence could imply microbial activity in the crust. This connection underscores why scientists are so keen to explore Mars—a planet that has intrigued researchers for decades.
NASA’s various missions, including rovers, landers, and orbiters, have all contributed valuable insights into Mars’ geology, climate, and potential for life, even if such life may have been extinct for millions of years. The Perseverance rover, for instance, has been actively exploring the Jezero Crater, an area believed to have once housed a lake of liquid water billions of years ago. The rover has collected various intriguing Martian rock samples, which NASA plans to send back to Earth through its Mars Sample Return program.
InSight, another critical mission that landed on Mars in November 2018, had a unique focus. It was designed to dig into Martian soil, monitor wind and dust events, and locate seismic activity. Before its mission ended in December 2022, InSight detected over 1,300 marsquakes and transmitted nearly 7,000 images of the Martian landscape back to Earth.
One of the significant findings from InSight involved seismic data that revealed boundaries at depths of approximately 6.2 miles (10 kilometers) and 12.4 miles (20 kilometers) below the surface, initially interpreted as changes in the porosity of subterranean rock. However, the authors of a recent paper propose that these boundaries could actually be cracks filled with water, which would fundamentally change our understanding of Mars’ interior.
To arrive at these conclusions, the research team conducted experiments to analyze how different types of seismic waves traveled through various rock types that were both dry, wet, and frozen—specifically using rock samples from Sweden for comparison. Their experiments demonstrated that seismic waves travel at different speeds through these materials. Hence, the variations in seismic velocities observed at the two Martian depths may indicate a transition from dry rock to wet rock, suggesting the presence of liquid water.
Katayama noted that while many studies have hinted at the existence of water on ancient Mars, their model proposes that liquid water still exists on Mars today. Meanwhile, InSight faced challenges as its robotic digging tool, known as the “Martian mole,” was unable to penetrate the Martian surface, which hampered efforts to explore the planet’s internal processes further.
If NASA can successfully achieve the Mars Sample Return mission, analyzing the samples collected by Perseverance could provide significant insights into whether life ever existed on Mars. Given the new findings regarding potential liquid water, the agency might also consider planning future missions that could further investigate the Martian subsurface.
