Using the James Webb Space Telescope (JWST), astronomers have discovered that Uranus’ moon Ariel may be hiding an ocean of liquid water underground.
Previous theories suggested that this occurred as a result of interactions between Ariel’s surface and charged particles trapped there. Uranus’ magnetosphere The process of releasing ionizing radiation and breaking down molecules to leave carbon dioxide is called “Radiolysis “
But new evidence J.W.S.T. The source of this carbon dioxide is not external to Ariel, but internal, possibly buried. Underground sea.
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Uranus and its rings as seen by the James Webb Space Telescope in 2023. (Images courtesy of NASA, ESA, CSA, and STScI)
Chemical elements and molecules absorb and emit light at characteristic wavelengths, leaving their individual “fingerprints” in the spectrum. The team that made this discovery used JWST to collect a spectrum of light from Ariel, which helped paint a picture of the chemical composition of Uranus’ moon.
Comparing this to a spectrum simulated from a chemical mixture in a laboratory on Earth, Ariel is the most Carbon dioxide-rich sediments This is the largest ice layer in the solar system. Not only has it increased the thickness of the ice by 10 millimeters (0.4 inches), Tidal Lock Although Ariel is permanently turned away from Uranus, it also revealed clear deposits of carbon monoxide for the first time.
“That shouldn’t happen. It has to go down to 30 Kelvin.” [minus 405 degrees Fahrenheit] “Before carbon monoxide stabilizes,” says team leader Richard Cartwright of the Johns Hopkins Applied Physics Laboratory (APL). It said in a statement “You’re definitely going to have to aggressively top up on carbon monoxide.”
That’s because Ariel’s surface temperature, on average, is about 65 degrees Fahrenheit (about 18 degrees Celsius) warmer than this critical temperature.
Cartwright acknowledges that radiolysis may explain some of this replenishment, but Voyager 2 flyby of Uranus in 1986 Studies of Uranus and its moons, as well as other recent findings, suggest that the interactions behind the radiolysis may be limited because Uranus’ magnetic field axis is misaligned by about 58 degrees from the orbital planes of its moons.
This means that most of the carbon/oxygen compounds found on Ariel’s surface could have been produced by chemical reactions in the liquid water ocean trapped beneath Ariel’s ice.
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Once produced in Ariel’s seep-water ocean, this carbon dioxide could leak through cracks in the icy shell of the Uranian moon, or be released explosively in powerful plumes.
The most detailed photograph yet of Uranus’ moon Ariel, taken by Voyager 2 in 1986. (Image source: NASA/JPL-Caltech)
Scientists have long suspected that the cracks and scars on Ariel’s surface indicate the presence of an active substance. Ice Volcano A volcano that spews icy mud instead of lava, and these mud eruptions are so powerful they could potentially spew material into Uranus’ magnetic field.
Most of the cracks and grooves seen in Ariel’s surface are on the side opposite Uranus. carbon dioxide and Carbon monoxide These features may explain why material leaking onto the surface of Uranus’ moons is more commonly found on this rear side of the icy body.
The JWST also found further chemical evidence that there is a subsurface ocean of liquid water. Carbonate Minerals Salt is produced when rocks encounter and interact with liquid water.
“If our interpretation of the carbonate features is correct, then it must have formed internally, so that’s a pretty big deal,” Cartwright explained. “That’s something that absolutely needs to be confirmed through future observations, modeling, or a combination of techniques.”
Uranus and its moons have not been visited by spacecraft since then. Voyager 2 About 40 years ago, this was not the primary mission of a spacecraft. In 2023, A 10-Year Survey of Planetary Science and Astrobiology He emphasized the need to prioritize a dedicated mission to the Uranus system.
Cartwright believes such a mission would provide an opportunity to gather valuable information about Uranus. Neptune Another ice giant in our solar system. Such a mission could also provide important data about other potentially ocean-bearing moons in these systems. This information would be used to identify exoplanets, or “Exoplanets ” ” outside the solar system.
“These new findings underscore just how fascinating the Uranus system is,” said team member National Aeronautics and Space Administration (NASA) Ian Cohen, a scientist at the Applied Physics Laboratory, said: How the solar system was formed To better understand the complex magnetospheres of planets and the Potential Ocean World Many of us in the planetary science community Future missions to explore Uranus “
The team’s investigation was released on Wednesday (July 24). Astrophysical Journal Letters .
