Water has been detected in a planet-forming disk using the Webb telescope

He discovered water in a disk of gas and dust around a young star 370 light-years from Earth. Astronomer Manuel Gödel of the University of Vienna says in the APA:

The researchers’ original goal was to examine the formation of the disk of the star “PDS 70,” which also orbits two gas giant planets in the disk’s outer region. Even if there was previously hope of gaining knowledge about the water content in the inner region of a disk of this type, that is, where rocky planets like Earth form, the evidence of water in this region, which has now been made available for the first time, is a very exciting discovery, says Gödel. The study, conducted by lead author Giulia Perotti of the Max Planck Institute for Astronomy in Heidelberg, is published in the journal Nature.

It is not yet clear how water got to Earth or Earth-like exoplanets. “Water itself is everywhere in the universe,” says co-author Güdel. The special thing is that the disk of the young star “PDS 70” is relatively old, 5.4 million years old, and forms planets.

Water is liable to disappear again, especially in the astral environment. According to previous theories, solid radiation from the star in the center of the disk and the first of the larger planets at its edge would violate the principle of water replenishment in the inner part of the disk and would favor the rapid decay of exactly that region in which astronomers expect the formation of Earth-like planets. Often only small dry planets in the form of rocky bodies can form with it.

Gaseous planets form around young stars “relatively quickly,” according to the Viennese researcher, that is, in the first million to three million years. Rocky planets often grow relatively slowly and after gaseous planets form.

The previous assumption was that young, rocky planets would not be supplied with water until later by the bombardment of water-containing asteroids that form in the outer region of the disk – just as comets and other small bodies form in our solar system, for example in the region of Neptune, which are turbulent in their orbit and then deflect into the water-rich bodies.

“We may now have found evidence that water may have been one of the first ingredients of rocky planets and that it has been present from birth,” Beiruti said. That may be the case, Gödel added, that Earth “may not have been cut off from its water supply” in its formation stage, despite the presence of the gaseous planets Jupiter and Saturn in our solar system.

The water around PDS 70 detected by the team appears as a hot steam with a temperature of 330 degrees Celsius (600 Kelvin). There is no evidence of planets near the center of PDS 70’s disk yet; The gas giant planets were discovered in their outer region a few years ago. As a source of water within the young star’s disk, the researchers believe that the water may be remnants of a water-rich original nebula that predates the disk stage. Or, as a second possibility, it could be caused by gas flowing from the outer edges of the young star’s disk, which could under certain conditions form water vapor from a mixture of oxygen and hydrogen gas. According to Perotti, the truth probably lies in a combination of both possibilities. One mechanism could be decisive – which one has yet to be elucidated.

One of the researchers’ goals now, Gödel said, is to find out how often water occurs in the planet-forming regions of developing disks around young stars and whether a general explanation can be derived from that. In the future, better and more computationally intensive models promise to be able to more accurately estimate the amount of water present across the radiation spectrum received by the James Webb telescope along with the signatures of water.

In any case, for terrestrial planets to form, a good average amount of available water is needed: enough for oceans to form on rocky planets, but not so much for biological evolution to work, Gödel said.