After the meteorite hit Mars two years ago, scientists have been able to analyse seismic energy that vibrated through the planet, which led to the discovery that the liquid-metal core of Mars is enveloped in a layer of molten-rock. This has greatly changed our knowledge of the planet’s core radius, now thought to be smaller than initially believed.
The data is reported by NASA’s InSight mission which landed a craft with a seismometer on Mars' surface, detecting many ‘marsquakes’ between the years of 2018 and 2022.
After a meteor hits the surface, the seismic waves are produced whose speed of travel changes based on the material they are travelling through. This helps scientists attain a better understanding of the planet's interior. Scientists are trying to discover more about what Mars' core consists of which would help them to understand its geological history and influence their research into whether it was ever suitable for establishing life there.
In July 2021 scientists were reporting that the radius of the liquid core was around 1830 kilometers. However, after the September impact which helped scientists discover the molten-rock layer, they now believe the core to be ranging from 1650 to 1675 kilometers.
The scientists are also theorizing that the layer of molten-rock might be left over from a magma ocean that once covered Mars.