How did the first solids that made up planets, moons, and asteroids form out of the “hot soup” that characterized our solar system’s earliest years? New research from Caltech analyzing pieces of a meteorite has found that, in the same way that snowflakes crystallize around grains of dust, ancient stardust grains leftover from long-gone suns may have been the seeds of our solar system’s earliest solids. The research was conducted in the laboratory of Francois Tissot , professor of geochemistry and Heritage Medical Research Institute Investigator, and appears in the journal Science Advances on J