“Farside quakes are intrinsically harder to detect because a great deal of energy is lost or diverted away as seismic waves travel through the planet.” “We needed both luck and skill to find, and then use, these quakes,” said lead author Jessica Irving, an Earth scientist at the University of Bristol in the United Kingdom. Credits: NASA/JPL-Caltech/University of Maryland.
InSight Detects Quakes That Entered Martian Core (Artist's Concept): This artist’s concept shows a cutaway of Mars along with the paths of seismic waves from two separate quakes in 2021. The distance proved crucial: The farther a quake happens from InSight, the deeper into the planet its seismic waves can travel before being detected. 18, 2021, the two temblors were the first identified by the InSight team to have originated on the opposite side of the planet from the lander – so-called farside quakes. The findings, which mark the first direct observations ever made of another planet’s core, were detailed in a paper published April 24 in the Proceedings of the National Academies of Sciences. By looking at seismic waves the instrument detected from a pair of temblors in 2021, scientists have been able to deduce that Mars’ liquid iron core is smaller and denser than previously thought. While NASA retired its InSight Mars lander in December, the trove of data from its seismometer will be pored over for decades to come. A pair of quakes in 2021 sent seismic waves deep into the Red Planet’s core, giving scientists the best data yet on its size and composition.
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