Water discovered in planetary system 370 light years from Earth

This young planetary system, known as PDS 70, is located 370 light years away. Its central star is about 5.4 million years old and cooler than the Sun. It is orbited by gas giants. Researchers recently identified one of them, PDS-70b, that may share an orbit with a third “sister” planet forming there.

Two distinct disks of gas and dust—the raw materials needed to form both stars and planets—surround the star. The inner and outer disks are about 8 billion kilometers apart. The gas giant planets orbiting the host star lie within these disks.

The James Webb Space Telescope has detected signs of water vapor in the inner disk, located less than 160 million kilometers from its host star. Astronomers believe this inner disk is where small, rocky planets similar to those in our Solar System would form if PDS 70 were like our Solar System. In our own planetary system, Earth is located 150 million kilometers from the Sun.

The study was published in the journal Nature.

"We have observed water in other disks of dust and gas, but not this close and not in a system where planets are gathering. We could not have made these measurements before the James Webb Telescope," study leader Giulia Perotti of the Max Planck Institute for Astronomy in Heidelberg, Germany, said in a statement.

Astronomers were surprised to find water vapor near the star of the PDS 70 planetary system, given its age. PDS 70 is relatively old for a star that hosts a planetary disk. The amount of gas and dust in disks in planetary systems decreases over time, either due to the host star’s activity or because material has clumped together to form planets. Water has never been detected in a planetary disk of this age before, leading astronomers to believe that water vapor could not have existed for such a long time and that any rocky planets there would be dry.

No planets have yet been detected forming in the inner disk, but all the ingredients needed to form them have been found. The presence of water vapor suggests that the planets may contain water in some form. Time will tell whether the planets form and whether they have the potential to support life.

"We found quite a high amount of small dust grains. Combined with the detection of water vapor, the inner disk is a very interesting place," said study author Rens Waters, professor of astrophysics at Radboud University in the Netherlands.

But where does steam come from?

It is possible that hydrogen and oxygen atoms have combined to form water molecules in the inner disk, or that ice molecules are moving from the colder outer disk to the hotter inner disk, causing the ice to turn into water vapor.

The water vapor is stable despite its proximity to the star because the dust layer protects it from being destroyed by the star's ultraviolet rays. The team plans to take further observations of the system with the James Webb Space Telescope in the future to learn more about the mysteries of how planetary systems form.

"This discovery is incredibly exciting because it probes the region where rocky planets similar to Earth form," said study co-author Thomas Henning, director of the Max Planck Institute for Astronomy.

According to VOV