• Study reveals two groups of meteorites have their origins in primitive asteroids

• These cosmic fossils contain matter from the birth of our Solar System

• The meteorites might have a shared asteroid parent, but evolved differently

A recent paper published in the Monthly Notices of the Royal Astronomical Society (MNRAS) has revealed new clues about the origin and evolution of the parent asteroids of two groups of meteorites, dating back to the formation of the Solar System. These meteorites are from asteroids formed at great distances from the Sun, containing the constituent elements of planets, and are known as Carbonaceous chondrites Vigarano (CV) and Karoonda (CK). 

The paper is based on the study of carbonate asteroids, so named because of their high organic matter content, which can be considered primitive because they contain solid materials that condensed around the Sun long before the Earth was formed. These asteroids are true fossils of the creation of the solid matter of our planetary system, as they cooled rapidly and their materials never melted. 

A group of scientists, led by Josep M. Trigo, researcher from the Institute of Space Sciences (ICE-CSIC), and Safoura Tanbakouei -former ICE researcher-, have been studying the mineral content and reflective properties of these two groups of meteorites for 5 years. They found that both carbonaceous chondrite groups could come from a same parent asteroid that was affected by collisions with other bodies.

These groups of chondrites have undergone a significant degree of metamorphism and fracture due to their exposure to collisions. The published paper explores a scenario in which the meteorites have their origin in the same asteroid, but evolved differently as a result of an impact that generated large fragments. 

The study measures and compares the reflectance of these two groups of chondrites and points to a shared deposit from which the meteorites CV and CK evolved after one or several collisions.  

According to this scenario, the CV and CK chondrites may have arisen from a common asteroid (most likely the asteroid known as Eos) that disintegrated into several fragments. Thus, due to impacts, the two groups of meteorites evolved separately.

This study concludes nearly a decade of research on Carbonaceous chondrites, as part of three projects in the Spanish plan for astronomy and astrophysics to study and recover meteorites and propose techniques for the possible future exploitation of parent asteroids.