The marsquake-hunting lander has detected two of the largest earthquakes to date on the far side of the planet.
The most sensitive seismometer ever designed was carried by NASA's InSight lander when it touched down on Mars. The mission has detected many marsquakes since it arrived, using the signals to map the planet's interior. Scientists on the mission said the two new earthquakes were special.
Anna Horleston, a seismologist at the University of Bristol in the U, said that the event dubbed S 1000a has a spectrum and duration unlike any other event previously observed.
Why is NASA looking for earthquakes?
The first earthquake of magnitude 4.2 occurred on August 25, 2021, in the Valles Marineris, a vast network of canyons on the opposite side of the planet.
One of the largest graben systems in the solar system is the Martian canyon complex, a valley with distinct fault blocks that are relatively lower than the blocks on either side of them. The detection of an event at this location is the first time that an event has been recorded at this location.
The second marsquake occurred on Sept. 18, 2021. The marsquake is unknown beyond that scientists have isolated it to the far side of Mars. The longest earthquake ever recorded on Mars lasted for 94 minutes.
The two marsquakes occurred in the shadow zone, where the seismometer can't directly detect P and S waves, the two main types of pressure waves produced by an earthquake. Researchers focused on what are known as PP and SS waves because the Mars core stops these waves from reaching the seismometer.
Unlike regular P and S waves that are halted by the planet's core, PP and SS waves are reflected at the surface and can provide information about the direction a quake moves along the surface.
Recording events within the core shadow zone is a real stepping-stone for our understanding of Mars, according to the study co-author Savas Ceylan.
There were differences between the two earthquakes. The scientists wrote in the study that S 1000a included energy up to 5 hertz. The location of the quakes is believed to be the reason for the difference, with s1000a matching the profile of shallow, crustal quakes and s0976a resembling the quakes.
Researchers can learn more about the nature of Mars, its interior, and its composition by using the data from the seismometer. The constraints on Mars' crust, mantle and core structure are now offered further insight by the detections presented in this new report.
The new report was published in April.
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