Discovery
NASA's Webb telescope detects carbon dioxide on Pluto's largest moon
The presence of the chemical suggests Charon's icy surface is altered by ultra-violet light and solar wind from the distant Sun, research shows.
![This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by NASA’s New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. [NASA, APL, SwRI]](/gc8/images/2024/10/02/47764-plutomoon-370_237.webp)
By AFP |
PARIS -- Scientists using the James Webb Space Telescope have detected carbon dioxide on the frozen surface of Pluto's biggest moon, Charon, for the first time, research revealed October 1.
The discovery of CO2, along with another chemical hydrogen peroxide (H2O2), could shed light on the icy worlds in the mysterious outer reaches of our Solar System.
Charon offers a rare glimpse into icy worlds beyond Neptune because -- unlike other Kuiper Belt objects including Pluto -- its surface is not obscured by highly volatile ices such as methane, Silvia Protopapa of the Southwest Research Institute in the US state of Colorado told AFP.
Protopapa is the lead author of a new study in the journal Nature Communications describing Webb's new discoveries on the biggest of Pluto's five moons.
'Piece of the puzzle'
Charon, which is around the width of France and half the size of Pluto, was first discovered in 1978.
When NASA's New Horizon spacecraft flew past Charon in 2015, it discovered the surface was mainly covered in water ice and ammonia, which are thought to give the moon its red and grey appearance.
It also showed that material from beneath the planet's surface was sometimes being exposed via craters.
This suggested to scientists that CO2 could also be on Charon's surface.
Objects in the Kuiper Belt, including Pluto and Charon, are thought to have been formed from the protoplanetary disc -- a circle of gas and dust that surrounded the infant Sun around 4.5 billion years ago.
The protoplanetary disc -- which is also thought to have contributed to the formation of Earth -- is thought to have contained CO2.
But New Horizon did not spot the gas on Charon.
The Webb telescope has now answered this "open question," because it measures longer wavelengths of light, allowing it to probe deeper, Protopapa said.
If one were to hypothetically step onto the surface of Charon, the surface would be a mixture of water ice and dry ice -- the solid form of CO2, she said.
More surprisingly, the Webb telescope also detected hydrogen peroxide, Protopapa added.
The presence of the chemical suggests Charon's icy surface is altered by ultra-violet light and solar wind from the distant Sun, according to the study.