Every time a story about the planet named for the Greek god of the sky is published, fans of Uranus wait for the first joke, pun or double entendre to respond angrily that the correct pronunciation of their favorite planet is YOUR-a-nus, not your-ANUS. Well, put down your pens – this story has to do with the moons of the giant gas planet and, if that brings yet another double entendre to mind, put the blame on the brain, not the poor writer. In this case, the moons are Miranda, Ariel, Umbriel, Titania, and Oberon, the five largest satellites of Uranus. Because of their similarities to Europa and Enceladus, big icy moons of Jupiter and Saturn, scientists now wonder of they could have subsurface oceans filled with alien life forms.
“If there’s liquid water there and it’s a little bit salty like ocean water on the Earth, then it can be conducting, meaning currents can flow in it.”
In a paper presented at the recent American Geophysical Union (AGU) fall meeting, MIT planetary scientist Benjamin Weiss explained how Voyager 2, way back in 1986, showed that these five big moons were roughly 50:50 combinations of rock and ice, and their surfaces showed signs of cryovolcanism – volcanoes that spew water, ammonia or methane instead of molten rock. When the moons pass through Uranus’s strange magnetic field, they could generate their own induced magnetic fields which would make the moons even more inhabitable. Magnetic fields would be detectable by future flyby satellites even landers and rovers, which is why Weiss and fellow Uranus moon fans of the scientific kind are pushing for missions to one or more of Miranda, Ariel, Umbriel, Titania, and Oberon.
“(A probe) getting close enough to one or more of the satellites to see this—you have to get close, meaning within a satellite radius, roughly—is unlikely to be a feature of an early…mission to Uranus (which likely wouldn’t arrive before 2042).”
David Stevenson, a planetary scientist at the California Institute of Technology in Pasadena, told Eos (the magazine and website of the AGU) that such a mission needs to be in the planning and budgeting phase now in order to reach one of those ocean-and-life-possible moons within a reasonable amount of time. Faster spacecrafts might help, but those are not in the near future either. Weiss knowns this but hopes talking about the possibility of life on so many of the larger moons in the solar system will get more people interested in missions to Uranus and Neptune.
Even if future missions find water but no life on the moons of Uranus, that would still be good news – water is needed for fuel to send probes back … or much farther out into space.
Uranus doesn’t deserve the double entendres anymore, and these discoveries will give its moons their own crack at fame. (Sorry!)