Molecules in Protostar Give Scientists 'Missing Link' in Understanding Origin of Water in Our Solar System

The discovery of water in the dust-cloud of a near-Earth young star is helping scientists discover how the vital molecule found its way onto comets, asteroids, and planets in our solar system.

Illustrations created by researchers studying protostar V883 Ori show water in gaseous form inside the star’s circumstellar disk.

The circumstellar disk is made up of a condensing cloud of gas and dust grains, where water in the form of ice can be found, Margot Leemker, an astronomer at Leiden University said. Protostar V883 Ori is useful to researchers because the temperature of its circumstellar disk means the water has turned from ice to gas, making it possible to study it using the Atacama Large Millimeter/submillimeter Array (ALMA).

“When these clouds collapse under their own gravity and form young stars, the water ends up in the disks around them. Eventually, the disks evolve and the icy dust grains coagulate to form a new solar system with planets and comets,” Leemker said. “We have shown that water that is produced in the clouds follows this trail virtually unchanged. So, by looking at the water in the V883 Ori disk, we essentially look back in time and see how our own Solar System looked when it was much younger."

“We can think of the path of water through the Universe as a trail. We know what the endpoints look like, which are water on planets and in comets, but we wanted to trace that trail back to the origins of water,” said John Tobin, an astronomer at the National Science Foundation’s National Radio Astronomy Observatory (NRAO) and the lead author on the new paper. “Until now, the chain of water in the development of our Solar System was broken. V883 Ori is the missing link in this case, and we now have an unbroken chain in the lineage of water from comets and protostars to the interstellar medium."

V883 Ori, also known as V883 Orionis, is a protostar located roughly 1,305 light years from Earth in the constellation Orion. Credit: ALMA (ESO/NAOJ/NRAO), J. Tobin, B.Saxton (NRAO/AUI/NSF) via Storyful