What was there first? Water or planets?
Could water be present in planet-forming disks before the formation of rocky planets? The James Webb Space Telescope may have found evidence for that. Webb has for the first time observed water in the inner disc around young star where at greater distance, giant planets have already formed. The research took place wihtin the MINDS collaborations led by the Max Planck Institute for Astronomy. Astronomers from Leiden University, Radboud University and the University of Groningen also contributed. They share their findings in Nature.
At issue is the inner disk of gas and dust around the young star PDS 70, 370 light year from Earth. Astronomers expect earth-like planets to form in that zone in the future. Two giant planets have already formed at greater distances from the star.
This is the first observation of water at a stage when the disc has already lost most of its material. This discovery provides evidence for a mechanism to supply potentially habitable planets with water already during their formation, in addition to the arrival of water from later asteroid impacts. This would increase the chances of 'habitability' of this planet at a later stage.
Read more about this discovery in the press release at astronomie.nl - JWST observations find water for the first time in the inner disk around a young star with giant planets
G. Perotti et al., ‘Water in the terrestrial zone of the PDS 70 disk’, Nature (2023). https://www.nature.com/articles/s41586-023-06317-9
Image: ESO/A. Müller et al.