The solar system favored chondrules over matrix within its first million years of existence, the first geochemical evidence of that sorting, a Yale-led study in Nature Astronomy reports^[4]. The earliest bodies in the outer solar system were built from 83% to 92% chondrules, said Damanveer Grewal, a Yale assistant professor and the study's first author^[3]. The work is important, said Ian Crawford, a planetary science professor at Birkbeck University of London who was not involved in the study. Large lunar settlements would require importing water, or the hydrogen needed to make water from oxygen in lunar rocks, he told CNN^[1]. The moon is where SpaceX now points. Elon Musk announced in February that the company had shifted from a Mars settlement to a 'self-growing city on the Moon,' which he said could be done in less than 10 years^[2].