Emily Chan
“Overall, these factors make Charon an invaluable target from which we can learn extensively,” said Protopapa.
“Our findings provide valuable insights into how processes such as sunlight exposure and cratering shape the surface of Charon and, by extension, other mid-sized icy bodies beyond Neptune’s orbit.”
The composition of stars, moons, and planets can be determined from wavelengths of light that reflect off their surfaces.
By using a technique called spectroscopy, traces of elements and chemical compounds can be identified.
Protopapa and colleagues compared JWST spectroscopic observations with measurements and detailed models of Charon’s surface.
They concluded that carbon dioxide is present in a water-ice-rich subsurface. Charon’s surface features multiple craters surrounded by water ice and ammonia-bearing compounds, suggesting that impact events exposed materials that were originally beneath the surface.
The team believes that the layer of carbon dioxide was from Charon’s interior and has been exposed to the surface due to impact events.
It was expected that carbon dioxide would be detected because the compound is known to be in regions of the protoplanetary disk from which the Pluto system was formed.
However, the detection of hydrogen peroxide was a surprise. Its presence on Charon indicates that ultraviolet light from the sun, energetic particles from the solar wind, and charged particles from beyond the solar system are altering the moon’s water-ice-rich surface.
The team plans to continue their studies of Charon to better understand icy TNOs. Their research was published in Nature Communications.
