Webb makes first-ever measurement of the physical and chemical properties of a potential moon-forming disk

Scientists have been trying to understand how planets and moons in our solar system formed. This formation happened over four billion years ago. Between that time and now, many structures have evolved.

Given these challenges, scientists have turned to exoplanets in their formative years. Understanding how these planets and their moons form could provide insights into the origins of our own solar system.

A new Webb study provided a direct measurement of the physical and chemical properties of the circumplanetary disk around CT Cha b — an exoplanet located 625 light-years away from Earth. The planet orbits a young star that is only 2 million years old. The star is still accreting circumstellar material.

Although Webb did not detect any moons in the observed circumplanetary disk, it found the disk to be rich enough to form moons in the future. Webb’s data suggests that the disk contains seven carbon-bearing molecules: diacetylene, hydrogen cyanide, propyne, acetylene, ethane, carbon dioxide, and benzene.

For this study, Webb observed CT Cha b using the medium resolution spectrograph of its MIRI (Mid-Infrared Instrument). The results of the study were posted in The Astrophysical Journal Letters. The research team aims to use Webb to carry out a comprehensive survey of similar objects in 2026.