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The two marsquakes differ in some important ways. S0976a is characterized by only low frequency energy, like many of the quakes identified so far on the planet, while S1000a has a very broad frequency spectrum. "[S1000a] is a clear outlier in our catalog and will be key to our further understanding of Martian seismology," Horleston said. S0976a is likely to have a much deeper origin than S1000a, she noted. "The latter event has a frequency spectrum much more like a family of events that we observe that have been modeled as shallow, crustal quakes, so this event may have occurred...

NASA's InSight lander arrived in November 2018 and started listening for Mars' heartbeat, we learnt something really remarkable: Mars is rumbling. To date, InSight has detected hundreds of marsquakes – enough to give us a detailed map of the Martian interior. Tkalčić and his colleague, geophysicist Weijia Sun of the Chinese Academy of Sciences, wanted to look for quakes that might have gone unnoticed in the InSight data. They used two unconventional techniques, only recently applied to geophysics, to hunt seismic events in the InSight data. Based on nine templates of known marsquakes, the pair detected 47 new seismic events,...