Recent observations from the James Webb Space Telescope (JWST) suggest that Ariel, one of the moons of Uranus, could harbor a subsurface liquid ocean. Ariel is one of 27 moons orbiting Uranus, the seventh planet from the sun. The discovery was made during a 21-hour observation period as part of the Moons of Uranus project. The focus was on detecting signs of water, ammonia and organic molecules, as well as carbon dioxide ice.
Carbon dioxide and carbon monoxide detected
Unexpectedly, JWST found carbon dioxide ice on Ariel, despite its distance from the sun, where such ice would normally turn to gas. This ice is mostly on the side of the moon that faces away from its orbit. Adding to the intrigue is the presence of carbon monoxide, detected for the first time on Ariel. Carbon monoxide is normally stable only at extremely low temperatures, much lower than Ariel’s average surface temperature of about 65 degrees Fahrenheit.
Implications for lunar geology and future missions
The researchers propose that the carbon dioxide ice could come from a subsurface ocean, with the ice escaping through cracks in the moon’s surface. Another possibility is that radiation from Uranus’ magnetic field breaks molecules apart, creating the observed ice. The study also suggests the presence of carbonates on Ariel’s surface, minerals that form when water comes into contact with rock. This could indicate a geologically active interior capable of supporting a subsurface ocean.
The findings have sparked interest in a possible mission to Uranus. The Uranus Orbiter and Probe (UOP) concept, a proposed NASA mission, could provide more detailed data. With launch opportunities in the early 2030s and the need for gravity assist from Jupiter, early action is critical to making this mission a reality.
In conclusion, Ariel observations with the James Webb Space Telescope suggest that an ancient or still existing subsurface ocean exists. This offers interesting possibilities for future research on Uranus and its moons.
