What are presolar grains and why do we study them?

Presolar grains are minerals that are older than anything else in our Solar System. They formed before the birth of our Solar System and a small fraction survived in primitive asteroids and comets. We extract presolar grains from fragments of these objects: unaltered meteorites, interplanetary dust particles and comet dust. We study the elemental and isotopic compositions of presolar grains to understand the presolar history of meteoritic matter. The interdisciplinary field of presolar grain research informally also called Astrophysics in the Laboratory is delivering a wealth of information on stars and our Galaxy that are not accessible through astronomical observations. One of our main motivations to study presolar grains, a surviving fraction of the source materials of our Solar System, is to improve our understanding of the history of our Galaxy.