Where did Earth’s Water Come From?

Water-bearing planetesimals, miniature astronomical structures from certain meteorite classes, delivered significant amounts of water to Earth in its early development, according to age data analysis and computational models described in Scientific Reports. “Thanks to these smaller, water-rich planets or their fragments in the form of asteroids or meteorites, Earth was able to avoid becoming a bone-dry, life-hostile planet during its growth process,” says lead author Wladimir Neumann.