An international team of planetary scientists led by astronomers at AOP have found an asteroid trailing behind Mars with a composition very similar to the moon’s. The asteroid could be an ancient piece of debris, dating back to the gigantic impacts that formed the moon and the other rocky planets in our solar system like Mars and the Earth. The research, which was published in the journal Icarus, also has implications for finding such primordial objects associated with our own planet.
Source:
https://phys.org/news/2020-11-mars-shepherd-moon-long-lost-twin.html