NASA has been recording seismic information from inside the surface of Mars using the InSight Lander’s seismometer. NASA says the data record is the first direct evidence of key boundaries inside the Red Planet’s interior. The goal was to help planetary scientists understand how rocky planets are formed.
Before recent data was recorded by the InSight Lander, scientists only had estimations thanks to models. The data recorded by InSight allows the researchers to check their models for the first time. NASA has said that InSight measured more than 170 tremors between February and September 2019.
The data was the first definitive seismic measurements taken on Mars, and InSight remains active recording more data. NASA says that the shape and strength of the waves the lander is recording allows the scientists to estimate the composition of Mars’ interior. Scientists say that the waves change slightly as they move through different types of rock.
Mars is much less tectonically active than Earth. That means there are relatively few marsquakes compared to earthquakes. Since the InSight lander is operating the only functional seismometer on Mars, scientists cannot employ methods that need a seismic network, which is commonly used here on Earth.
Since only one seismometer is available, scientists use a data technique called ambient noise autocorrelation, a method meant to extract reflections produced at the boundaries of Martian zones beneath the crust and mantle. Those zones are 22 miles underneath the lander. A transition zone between the minerals olivine and wadsleyite lies under the lander at a depth of 690 to 727 miles. The boundary between the mantle and core are 945 to 994 miles under the lander.