Early Solar System Built From Melted Rock, Not Icy Dust, Study Finds
A study led by Damanveer Grewal at Yale reports that the solar system's earliest solid materials were dominated by chondrules, which formed through intense heating, rather than volatile-rich matrices. The team looked at the first million years of solar system history, a window with no surviving pristine samples because aluminum-26 decayed quickly. Their findings support a fire-first picture for the first planetary building blocks.
A Yale-led team, headed by Damanveer Grewal, examined the solar system’s opening million years. That era lacks unaltered samples because Aluminum-26, with a roughly 705,000-year half-life, heated early planetesimals internally and blurred their original makeup.
Using iron meteorites, the researchers inferred sulfur levels and iron oxidation states. Their models suggest matrices made up only 8–17% of the material, implying chondrules dominated. In a spinning protoplanetary disk, denser melted-rock droplets could cluster into planetesimals while fluffier, volatile-rich dust was dispersed.
This finding may shape how planetary scientists and science communicators describe early solar system formation, potentially refining models taught in classrooms and museums. Meteorite researchers and space mission planners could use it to interpret samples and target bodies. The public may encounter a clearer fire-first narrative, though practical effects remain indirect and speculative until further studies confirm the result.