More water than Earth’s ocean: A planet is taking shape next to a young sun

Astronomers have discovered an ocean of water vapour around a young sun where new planets are forming in deep space.

The new findings are key as, so far, astronomers have not been able to map how water is distributed in a stable, cool disc — the type of disc that offers the most favourable conditions for planets to form around stars.

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“I had never imagined that we could capture an image of oceans of water vapour in the same region where a planet is likely forming,” Stefano Facchini, an astronomer at the University of Milan, Italy, who led the study, said in a statement.

The findings, published in the journal Nature Astronomy, reveal that there is at least three times more water than in all of Earth’s oceans combined in this region. The region is the inner disc of a young Sun known as HL Tauri.

It is located 450 light years away from Earth.

Astronomers said that a large volume of water vapour was found in the region where a known gap in the HL Tauri disc exists. Ring-shaped gaps are carved out in gas- and dust-rich discs by orbiting young planet-like bodies as they gather up material and grow.

“Images reveal a substantial quantity of water vapour at a range of distances from the star that includes a gap where a planet could potentially be forming at present,” says Facchini.

The team used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile at an elevation of 5000 metres to look at the sun-like star. The observations with ALMA allowed astronomers to determine the distribution of water in different regions of the disc.

“It is truly exciting to directly witness, in a picture, water molecules being released from icy dust particles,” Elizabeth Humphreys, an astronomer at ESO added.

Astronomers are excited to share the results which show how the presence of water may influence the development of a planetary system, just like it did some 4.5 billion years ago in our own Solar System.