New Evidence Suggests Liquid Water Under Mars’ Surface
Research published late last year has presented intriguing evidence that could bolster the possibility of microbial life on Mars. Scientists have detected “seismic discontinuities in the Martian crust,” which they believe may indicate the presence of liquid water beneath the planet’s surface. This finding fuels the idea that microbial life may persist on Mars, even today, hidden beneath its dry, rocky exterior.
Mars: A Compelling Venue for Astrobiology
Mars has long captivated scientists due to its ancient past, which is thought to share similarities with Earth’s early history. With its proximity to our planet and a history that may have supported life, Mars has been a focal point in the search for extraterrestrial life. The discovery of potential liquid water beneath its surface is a significant development in astrobiology, suggesting that Mars might still harbor the conditions necessary for life.
According to Ikuo Katayama, a planetary scientist at Hiroshima University and co-author of the study, “If liquid water exists on Mars, it could mean the presence of microbial activity” within the Martian crust. This notion gives scientists renewed hope that life could have once thrived, or might still exist in some form, beneath Mars’ surface.
Perseverance Rover: Gathering Data from Jezero Crater
NASA’s Perseverance rover has been exploring the western edge of Jezero Crater, a site believed to have once held a large body of liquid water billions of years ago. Perseverance has collected fascinating Martian rock samples, which will eventually be brought back to Earth through the Mars Sample Return program. The rover’s findings continue to shed light on the planet’s past environment and raise the possibility that conditions once supported life.
InSight: Detecting Seismic Activity and Uncovering Martian Secrets
NASA’s InSight lander, which arrived on Mars in November 2018, has played a key role in examining the planet’s interior. InSight’s mission was to probe the Martian surface, listen to dust devils and wind patterns, and—crucially—measure seismic activity. Before its decommissioning in December 2022, InSight recorded over 1,300 marsquakes and sent nearly 7,000 images back to Earth, providing valuable insight into the planet’s geological processes.
One of the most significant findings from InSight’s seismic data was the detection of boundaries at depths of 6.2 miles (10 kilometers) and 12.4 miles (20 kilometers) beneath Mars’ surface. These boundaries were initially thought to be due to changes in rock porosity, but the research team now believes that they could indicate cracks in the Martian subsurface filled with water.
Seismic Data and the Presence of Water
To investigate this further, the team used seismic wave measurements taken on Mars and compared them to similar rock formations in Sweden. Their experiments showed that seismic waves travel differently through dry, wet, and frozen materials. This difference in seismic velocity suggests that the boundaries detected by InSight could mark a transition from dry rock to water-filled rock beneath the Martian surface, potentially confirming the presence of liquid water.
Katayama noted that while many studies have suggested the presence of water on ancient Mars, “our model indicates the presence of liquid water on present-day Mars,” offering a fresh perspective on the planet’s current conditions.
Challenges and Future Exploration
Despite InSight’s valuable seismic data, NASA faced a setback with the failure of its digging tool, the Martian mole. The mole was designed to dig into the Martian surface to further investigate the planet’s internal structure, but it encountered difficulties, preventing scientists from gaining deeper insights into Mars’ geology.
Looking forward, if NASA successfully carries out the Mars Sample Return mission, the Perseverance rover’s collected samples could provide invaluable clues about whether life ever existed on Mars. However, the recent seismic findings suggest that more ambitious exploration might be needed. In particular, sending a more capable digging tool or an earth-mover to the Red Planet could be crucial for understanding Mars’ subsurface and its potential for supporting life.
