JWST detects CO₂ and H₂O₂ on the surface of Charon
A study in which IAS participated has just revealed the presence of new molecules on the surface of Charon, Pluto's largest moon, thanks to observations from the James Webb Space Telescope (JWST). While a NASA mission, New Horizons, had already mapped this moon in 2015, recent observations by JWST have detected carbon dioxide and hydrogen peroxide on its surface for the first time, enriching our understanding of its chemical composition.
Unlike other large Kuiper Belt objects such as dwarf planets, Charon's surface is not covered in volatile ices such as methane, making its overall composition more accessible to the remote sensing analysis. The discoveries made possible by JWST open the way to in-depth studies of the processes that shape the surfaces of these icy objects. Thus, the presence of hydrogen peroxide (H₂O₂) indicates that Charon's surface, rich in water ice, is undergoing modifications caused by ultraviolet light from the Sun, and energetic particles from the solar wind and cosmic rays. For carbon dioxide (CO₂), the preferred interpretation is that the CO₂ in the upper layer originates from the interior and has been exposed to the surface through cratering events. Carbon dioxide is known to be present in regions of the protoplanetary disk from which the Pluto system formed. These results provide valuable insight into the chemical and physical evolution of icy objects in the most distant regions of the Solar System.
Spectrum of light reflected from the surface of Charon, obtained by the New Horizons mission (in pink) and JWST (white), highlighting the signatures of CO₂ and H₂O₂. Background: View of Charon observed by New Horizons. Credit: S.Protopapa/SwRI/NASA/ESA/CSA/STScI/JHUAPL.
Contact at IAS : Rosario Brunetto, CNRS, IAS / OSUPS
Links:
- CNRS Terre & Univers news item
- Scientific paper: Protopapa, S., Raut, U., Wong, I. et al. Detection of carbon dioxide and hydrogen peroxide on the stratified surface of Charon with JWST. Nat Commun 15, 8247 (2024). DOI:10.1038/s41467-024-51826-4
