“We can now trace the origins of water in our Solar System to before the formation of the Sun,” said lead study author John J. Tobin, an astronomer at the National Radio Astronomy Observatory, in a statement.
“The composition of the water in the disc is very similar to that of comets in our own Solar System. This is confirmation of the idea that the water in planetary systems formed billions of years ago, before the Sun, in interstellar space, and has been inherited by both comets and Earth, relatively unchanged.”
Detecting water molecules in planetary disks can be a difficult task.
“Most of the water in planet-forming discs is frozen out as ice, so it’s usually hidden from our view,” said study coauthor Margot Leemker, a doctoral student at Leiden Observatory in the Netherlands, in a statement.
Gaseous water is easier to detect than ice because the molecules emit radiation as they move.
The disk around V883 Orionis is unusually warm due to outbursts of energy released by the star, which turned the ice to gas and enabled the researchers to detect it, Tobin said.
The team detected at least 1,200 times the amount of water in Earth’s oceans in the planet-forming disk.