Were the Oceans of Earth Born with the Moon?

The Earth is the lone body in the inner solar system known to have vast quantities of liquid water. Life on our world came about, in part, due to the stabilizing effects the Moon has on our planetary climate. What may seem unusual, however, is that water arrived on Earth at nearly the exact same time the Moon formed. A new study reveals an accidental game of planetary billiards that may have helped define who we are, as a planet.

As our Solar System took shape, roughly 4.5 billion years ago, the planetary disk appears to have divided into dry and wet regions. Water-rich carbonaceous bodies formed in the outer part of the Solar System, while drier, non-carbonaceous objects came into being closer to the Sun. Therefore, examining isotopes (specific varieties) of the silver/white metal molybdenum in meteorites allows researchers to determine the ultimate origin of rocks from beyond our world.

Is the formation of the Moon tied in with the mystery of how Earth became a water world where there shouldn’t be one? Image credit: George Desipris/Pexel

“The molybdenum isotopes allow us to clearly distinguish carbonaceous and non-carbonaceous material, and as such represent a ‘genetic fingerprint’ of material from the outer and inner solar system,” explains Dr. Gerrit Budde of the Institute of Planetology in Münster.

Concentrations of various isotopes of molybdenum in the mantle of the Earth suggest much of the molybdenum located there came from the outer solar system. This idea is…