The solar wind, comprised of solar particles largely made of hydrogen ions, created water on the surface of dust grains carried on asteroids that smashed into the early Earth, according to a paper published in the journal Nature Astronomy. Daly et al. used atom probe tomography to directly observe an average ~1 mol% enrichment in water and hydroxyls in the solar-wind-irradiated rim of an olivine grain from the S-type asteroid Itokawa. Image credit:...
