A new study by US space agency Nasa shows that four of Uranus’ largest moons might contain an ocean layer between their cores and icy crusts. This is the first study to elaborate on the evolution of the interior makeup and structure of all five large moons: Ariel, Umbriel, Titania, Oberon, and Miranda, according to Nasa.
The research, through a fresh look at the data from Nasa’s Voyager spacecraft, along with new computer modelling, suggests four of the moons—Ariel, Umbriel, Titania, and Oberon—hold oceans that could be miles deep. At least 27 moons orbit Uranus, with the four largest ranging from Ariel to Titania.
The new study, published in the Journal of Geophysical Research could help future missions investigate the moons, said lead author Julie Castillo-Rogez of Nasas Jet Propulsion Laboratory in Southern California, in a statment on Nasa's website.
“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,” she said in Nasa’s statement. “So, there are mechanisms at play that we don’t fully understand.” The new study examines these mechanisms and how they could be relevant to the other bodies in the solar system that could be rich in water but have limited internal heat, she added.
The re-analysis shows how the persistent internal heat of the Uranian moons and some chemicals could make them have water bodies despite their location in the outer reaches of the solar system. "Finding oceans in the Uranian moons would increase the prospect that [...] ocean worlds are frequent in our solar system, and maybe — by extension — in other solar systems," Castillo-Rogez, told Space.com.
Another important finding suggests that chlorides and ammonia are likely to be abundant in the oceans of the icy giant’s largest moons. The latter is long known to act as antifreeze. Moreover, the study suggests that the likely presence of salts in the water could be another source of antifreeze, maintaining the bodies' internal oceans, according to Nasa.
Nasa is currently working on a potential mission to Uranus, with the placeholder name of Uranus Orbiter and Probe (UOP). UOP would include an orbiter to gather data about the ice giant and its moons and a probe that would examine the planet's atmosphere for first-hand information, according to Space.com. The current research can help scientists design instruments that can probe the deep interior of such bodies for liquid.