The InSight Mars lander may have retired in December, but the data from its seismometer will be studied for years to come. Scientists have been able to deduce that Mars’ liquid iron core is smaller and denser than previously thought by looking at seismic waves the instrument detected from a pair of temblors in 2021. The findings, which mark the first direct observations ever made of another planet’s core, were detailed in a paper published in the Proceedings of the National Academies of Sciences. 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 distance proved crucial: The farther a quake happens from InSight, the deeper into the planet its seismic waves can travel before being detected.
