Presolar grains are microscopic mineral grains that formed in the outer atmosphere of dying stars before being incorporated into the Solar System during its formation. These grains are typically smaller than a few micrometers in size and are composed of a variety of minerals such as silicates, oxides, and carbides. By studying presolar grains, researchers can gain insights into the processes that occurred in stars before their death and shed light on the conditions present in the early Solar System. Presolar grains are often found in meteorites and can be extracted and analyzed using sophisticated laboratory techniques such as scanning electron microscopy and isotopic analysis.