BLUF

NASA’s Mars rover has sent back detailed information on the planet’s construction and seismic activity, giving insight into how Mars was formed.

Summary

Launched in 2018, NASA's lander InSight mission reveals how Mars has evolved and how it is different from Earth. This article makes the following points:
Four billion years ago, Mars and Earth were alike and discovering what's beneath Mars surface might help us understand why the two planets had different fates. 
  • Mark Panning, the project scientist for the InSight mission, said that since InSight landed on Mars in 2018, its seismometer has helped the team to see what's happening underneath Mars' surface and has enabled NASA to create a 3D map of Mars's interior using seismometer data.
  • Simon Stähler's team studied the planet's core.  Stähler concluded that Mars consists of molten nickel-iron and is much bigger than was previously thought.
  •  Amir Khan's team looked at the Martian mantle and found that while similar to Earth's, it is thicker and lacks tectonic plates. 
  • The third team, led by Brigitte Knapmeyer-End run, analysed the Martian crust, and found it's thinner than expected.
The American Association for the Advancement of Science  AAAS has published papers on the work of the Insight Mission as follows: