The five large moons of Uranus — Miranda, Ariel, Umbriel, Titania, and Oberon — are important targets for future spacecraft missions. Studying these bodies would help address the extent of habitable environments in the outer Solar System. To motivate and inform the exploration of these moons, planetary researchers modeled their internal evolution, present-day physical structures, and geochemical and geophysical signatures that may be measured by spacecraft. They predicted that if the moons preserved liquid until present, it is likely in the form of residual oceans less than 30 km (18.6 miles) thick in Ariel, Umbriel, and less than 50 km (31 miles) in Titania, and Oberon.
At least 27 moons circle Uranus, with the four largest ranging from Ariel, at 1,160 km (720 miles) across, to Titania, which is 1,580 km (980 miles) across.
Planetary scientists have long thought that Titania, given its size, would be most likely to retain internal heat, caused by radioactive decay.
The other moons had previously been widely considered too small to retain the heat necessary to keep an internal ocean from freezing, especially because heating created by the gravitational pull of Uranus is only a minor source of heat.
“Our work could inform how a future mission might investigate the moons, but the paper also has implications that go beyond Uranus,” said Dr. Julie Castillo-Rogez, a researcher at NASA’s Jet Propulsion Laboratory.
“When it comes to small bodies — dwarf planets and moons — planetary scientists previously have found evidence of oceans in several unlikely places, including the dwarf planets Ceres and Pluto, and Saturn’s moon Mimas.”
“So there are mechanisms at play that we don’t fully understand. This paper investigates what those could be and how they are relevant to the many bodies in the solar system that could be rich in water but have limited internal heat.”
In their study, the researchers revisited findings from NASA’s Voyager 2…
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