Water on Earth is omnipresent and essential for life as we know it, and yet scientists remain a bit baffled about where all of this water came from: Was it present when the planet formed, or did the planet form dry and only later get its water from impacts with water-rich objects such as comets?

A new study in the journal Science suggests that the Earth likely got a lot of its precious water from the original materials that built the planet, instead of having water arrive later from afar.