Scientists uncover hidden shards of Mars’ violent birth, frozen for billions of years
Mars isn’t the neatly layered world we once imagined — its mantle is filled with ancient, jagged fragments left over from colossal impacts billions of years ago. Seismic data from NASA’s InSight mission revealed that these buried shards, some up to 4 km wide, are still preserved beneath the planet’s stagnant crust, acting as a geological time capsule.
ScienceDaily 
Scientific American