In a cosmic twist worthy of a sci-fi plot, scientists using the James Webb Space Telescope (JWST) to peer deep into space have discovered a planet-forming disk that defies expectations. Instead of the usual steamy soup of water vapor, this disk is bubbling with carbon dioxide and barely a trace of water. The discovery, led by Jenny Frediani at Stockholm University, is shaking up what we thought we knew about how planets like Earth form.
When stars are born, they form within a swirling disk of gas and dust, the nursery where planets eventually take shape. Usually, icy pebbles from the outer disk drift inward, melt in the warmth, and release water vapor. But this time, JWST’s MIRI instrument picked up something unexpected: a strong carbon dioxide signal and almost no water.
So what’s cooking up all this CO₂? Arjan Bik, another researcher at Stockholm University, suspects ultraviolet rays might be rewriting the disk’s chemistry.
The team also spotted rare versions of carbon dioxide, molecules with heavier isotopes, such as carbon-13 and oxygen-17 or -18. These could help solve mysteries about the chemical fingerprints found in ancient meteorites and comets from our own Solar System.
Webb observed the chemical signature of carbon-rich dust grains in the early Universe
This peculiar disk lives in NGC 6357, a massive star-forming region about 53 quadrillion kilometers away. The find comes courtesy of the XUE (eXtreme Ultraviolet Environments) collaboration, which studies how harsh radiation affects planet-making chemistry.
Thanks to JWST’s MIRI instrument, a powerful infrared camera and spectrograph co-developed by scientists at Stockholm University and Chalmers, astronomers can now peek into dusty, distant disks with stunning clarity. By comparing chaotic star-forming zones with quieter ones, researchers are beginning to map out the diverse origins of planets.
Journal Reference:
- Jenny Frediani, Arjan Bik, María Claudia Ramírez-Tannus, Rens Waters, Konstantin V. Getman, Eric D. Feigelson, Bayron Portilla-Revelo, Benoît Tabone, Thomas J. Haworth, Andrew Winter, Thomas Henning, Giulia Perotti, Alexis Brandeker, Germán Chaparro, Pablo Cuartas-Restrepo, Sebastian Hernández A., Michael A. Kuhn, Thomas Preibisch, Veronica Roccatagliata, Sierk E. van Terwisga, Peter Zeidler. XUE: The CO2-rich terrestrial planet-forming region of an externally irradiated Herbig disk. Astronomy, 2025; 701: A14 DOI: 10.1051/0004-6361/202555718