Meteorites have told Imperial researchers the likely far-flung origin of Earth’s volatile chemicals, some of which form the building blocks of life.

They found that around half the Earth’s inventory of the volatile element zinc came from asteroids originating in the outer solar system—the part beyond the asteroid belt that includes the planets Jupiter, Saturn, and Uranus. This material is also expected to have supplied other important volatiles such as water.

Volatiles are elements or compounds that change from solid or liquid state into vapor at relatively low temperatures. They include the six most common elements found in living organisms, as well as water. As such, the addition of this material will have been important for the emergence of life on Earth.

Prior to this, researchers thought that most of Earth’s volatiles came from asteroids that formed closer to the Earth. The findings reveal important clues about how Earth came to harbor the special conditions needed to sustain life.

Senior author Professor Mark Rehkämper, of Imperial College London’s Department of Earth Science and Engineering, said, “Our data show that about half of Earth’s zinc inventory was delivered by material from the outer solar system, beyond the orbit of Jupiter. Based on current models of early solar sys