Meteorites brought water to Earth earlier than thought

A new study suggests that Earth’s water arrived much earlier than previously thought, according to a recent release from Woods Hole Oceanographic Institution. Many scientists argue that Earth was dry at first and later gained water from comets. The new theory speculates that a type of early meteorites called carbonaceous chondrites brought water to Earth earlier.

The scientists measured hydrogen isotopes from fragments from an asteroid that formed when the Earth was in its early building stages. They found a ratio of the asteroid’s hydrogen isotopes matched the that of the carbonaceous chondrites. The institution’s researchers believe their findings could also mean that apparently dry planets once held water.

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Top image: Illustration of the early solar system. The Dashed white line represents the snow line where the hotter inner solar system, where water ice is not stable transitions into the outer solar system, where water ice is stable. (Credit: Jack Cook, Woods Hole Oceanographic Institution)