The interior of Mars hides water that could be home to life. A new analysis of seismic data from the InSight mission suggests so.
The InSight spacecraft studied Mars seismic activity between c 2018 and 2022. It was able to record a number of tremors and vibrations, many of which were caused by meteorite impacts. Scientists used this data to scan the planet’s interior.
The fact is that different types of seismic waves travel through the planet in different ways. For example, so-called S-waves cannot pass through water and travel at a slower speed than P-waves. Therefore, the presence, absence, and arrival time of S-waves can be used to determine what the subsurface looks like. In addition, P-waves can travel faster through higher density rocks and slower through lower density rocks. Therefore, their rate can help determine the density of the material as well as the nature of its changes.
Analysis of the seismic data collected by InSight revealed a boundary at depths ranging from 10 km and 20 km. It was previously interpreted as abrupt transitions in the porosity or chemical composition of the Martian interior. However, scientists Ikuo Katayama of Hiroshima University and Yuya Akamatsu of the Marine Geodynamics Research Institute interpreted them as potential evidence of water. They believe InSight seismic data indicate a boundary between dry fractures and water-filled fractures.
To test their hypothesis, the scientists measured the speed of seismic wave propagation through rocks with the same structure and composition as typical Martian rock under wet, dry and frozen conditions. The experiment showed that they are significantly different. This confirms the interpretation that the boundary found indicates a transition from dry to wet rock, rather than changes in porosity and chemical composition.
According to the researchers, the findings provide strong evidence for the existence of liquid water beneath the surface of modern Mars. And if liquid water exists in the planet’s interior, it may well be home to microbial life.
According to Phys.org
