Scientists have found what they say is the “missing link” in the search for where the water in our solar system came from.

Gaseous water was seen around a distant star, in the planet-forming disc that surrounds it.

That observation helps explain how water came from star-forming gas clouds onto planets like Earth – and supports the idea that the water that surrounds us is older than our Sun.

“We can now trace the origins of water in our Solar System to before the formation of the Sun,” said John J Tobin, an astronomer at the National Radio Astronomy Observatory, USA and lead author of the study published recently in Nature.

Newly forming star system reveals water likely existed in our solar system before the sun.

Scientists made the finding by looking at V883 Orionis, a disc of material around a star about 1,300 light years from Earth. That planet-forming disc is created alongside the star, and the material in it will eventually start clumping together to make bigger objects such as planets.

Scientists spotted gaseous water within that material. By looking at the composition of the water, they can find when and where it was formed.

Previous research has shown that water in Solar System comets is similar to that of Earth, suggesting that previous comets might have delivered it to our planet. But there was a missing link in that process: That which connected young stars to comets.

“V883 Orionis is the missing link in this case,” Tobin said. “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.”