NASA's latest scoop: Could life swim in the hidden oceans of Uranus's moons?
Fresh analysis of data, collected by the Voyager probe during its flyby near Uranus, in tandem with the usage of innovative computer modelling, led NASA scientists to the conjecture that four of Uranus's five largest moons harbor an ocean layer sandwiched between their cores and icy crusts.
The Moons of Uranus
Uranus is orbited by 27 moons, the largest of which are Titania, Oberon, Umbriel and Ariel. The fifth being Miranda, but our focus here lies with the first four. The smallest, Ariel, boasts a diameter of about 721 miles, while the most sizable, Titania, stretches to about 982 miles in diameter. In comparison, Earth's Moon is more than twice as big, sporting a diameter of about 2160 miles, even though our planet is over 14 times smaller than Uranus.
Long considered by scientists is the idea that Titania, due to its size, retains internal heat from radioactive decay of elements. Other moons were thought to be too small to accomplish this. This heat is crucial in keeping the ocean, concealed beneath an icy crust, fluid. A secondary source of heat arises from the warming caused by the motion generated by Uranus's gravitational influence, although this doesn't generate a substantial amount of power.
Paying Attention to Uranus and its Environs
Throughout this year, the concerted efforts of scientists have been aimed at surveying and studying Uranus. Focusing on the icy giant is geared towards potentially launching an exploratory mission in the future. If a probe is dispatched to study the eccentrically tilted planet, it would be prudent to include an examination of its most prominent moons.
Previously, planetary scientists have uncovered evidence pointing to the existence of internal oceans in small celestial bodies like dwarf planets and moons. The signs even pointed towards such unlikely places as Ceres and Pluto, as well as Saturn's moon Mimas.
Scientists harnessed the data from Voyager 2, which made a close flyby of Uranus back in the 1980s, and from contemporary observations. They used this information to craft computer models that provide some perspective on what these moons' interiors might look like. Telescopic observations suggest that Ariel may even have icy volcanoes on its surface.
What's Hidden Inside?
Scientists utilized modelling to gauge the porosity of the moons' outer shells and determine if the internal oceans are sufficiently insulated from the vacuum of space to keep their internal heat. For Titania and Oberon, the internal heat of these celestial bodies might be substantial enough to support sustaining simple life forms in their subterranean waters.
Even the smallest of the five, Miranda, has surface features that imply it may have been able to preserve heat. However, thermal modelling suggests that if there ever was liquid water there, Miranda likely lost it long ago, supplanted by icy frost. Internal heat isn't everything though, as the modelling also uncovered that there's probably ample ammonia in these moons' undersea waters, which acts as an anti-freeze. Likewise, high concentrations of a similarly acting salt were found.
