I have a friend who’s obsessed with The Little Mermaid. So if I’m going to write a post about Ariel, one of the moons of Uranus, it would be a real shame if I couldn’t make some sort of Little Mermaid reference.
Unfortunately, we know precious little about Ariel, or any of Uranus’s moons, for that matter. Only one spacecraft has ever visited: NASA’s Voyager 2, way back in 1986. And the data Voyager 2 sent back gives us a frustratingly incomplete picture.
What I can tell you is that Ariel’s surface is made of ice, specifically water ice and carbon dioxide ice. One hemisphere appears to have more carbon dioxide than the other, according to this paper from Icarus. And according to this profile piece from NASA, Ariel is the shiniest of Uranus’s moons–it reflects more sunlight than the others. Oh, and Ariel’s surface appears to be younger than the surfaces of those other moons as well. That might be important!
In fact, according to this article from Scientific American:
[The Voyagers 2] flyby revealed Ariel to be relatively smooth, as if its surface was being continually renewed by activity deep within. It is currently believed to be the only ocean world in the Uranian system.
A word of caution: that Scientific American article says a lot of highly speculative, highly conjectural stuff. Take it with a grain of sodium chloride.
However, in the absence of better, more detailed information about Uranus and its moons, it sounds like Ariel could maybe possibly be Uranus’s version of Europa or Enceladus. It could possibly be a moon with an icy crust floating atop an ocean of liquid water. It might even be the kind of environment that could support life. There might even be….
But no, I shouldn’t make a claim like that. It would be irresponsible of me as a science blogger. Voyager 2’s data was too limited, and subsequent observations by Hubble or other Earth-based telescopes can only tell us so much. Until our next mission to Uranus (whenever that might be), we really can’t say what might be hiding beneath the icy crust of Ariel.