A team led by the Southwest Research Institute has made significant discoveries on Pluto's largest moon, Charon, by detecting carbon dioxide and hydrogen peroxide on its frozen surface using the James Webb Space Telescope (JWST). These findings enhance Charon's known chemical inventory, which already included water ice, ammonia-bearing species, and organic materials responsible for its distinct coloration.
Charon, a midsized Kuiper Belt object, has been geologically mapped since the New Horizons mission flew by the Pluto system in 2015. Unlike larger Kuiper Belt objects, Charon's surface is not obscured by volatile ices, providing valuable insights into geological processes influenced by sunlight exposure and cratering.
The JWST's advanced observational capabilities allowed the team to explore Charon's surface at longer wavelengths, revealing the presence of carbon dioxide primarily as a surface veneer over a water-ice-rich subsurface. The team hypothesizes that this carbon dioxide originates from the moon's interior, exposed through cratering events.
Additionally, the presence of hydrogen peroxide indicates that Charon's surface is actively altered by solar ultraviolet light and energetic particles. This discovery adds a layer of complexity to our understanding of icy bodies in the outer solar system.
Future JWST observations are expected to target spectral gaps not covered in the current data, which could lead to further discoveries related to Charon's chemical composition and the mechanisms influencing its surface.