On December 19, 2018, NASA’s InSight mission made history by deploying the first seismometer on Mars using its distinctive white robotic arm and black grappling hand. This groundbreaking instrument has provided invaluable insights into the Martian geology, revealing crucial details about the planet’s crust thickness, mantle temperature, and the composition and depth of its core and atmosphere.
InSight’s seismometer has successfully detected marsquakes, the Martian equivalent of earthquakes, marking a significant milestone in planetary science. Unlike Earth, where seismic activity is driven by tectonic plate movements, Mars has a single expansive crust that features various faults and fractures as it gradually shrinks and cools. This process causes the crust to crack, and InSight recorded over 1,300 marsquakes originating from considerable distances.
By analysing the seismic data gathered, researchers were able to determine the speed at which these marsquakes travel through the Martian landscape. This information is vital, as it helps scientists understand the types of materials present beneath the surface. The velocity of seismic waves is influenced by the composition of the rocks, their structural integrity, and the presence of fluids filling any cracks.
To enhance their findings, the researchers employed mathematical models based on rock physics typically used on Earth to identify underground reservoirs such as oil fields and aquifers. Their modelling indicated that the data from InSight is most consistent with a substantial layer of igneous rock beneath the surface, believed to be interspersed with liquid water.
In summary, InSight’s deployment of the seismometer has initiated a new era of Martian exploration, providing critical information about the planet’s geological structure and contributing to our understanding of its formation and evolution. The findings not only enhance our knowledge of Mars but also offer a comparative perspective on planetary processes throughout the solar system.