Models suggest that four of Uranus’ moons, Ariel, Umbriel, Titania, and Oberon, likely have an ocean layer beneath their surfaces. Miranda, however, needs to be bigger to maintain one.
Credits: NASA/JPL-Caltech
Imagine the surprise of scientists when an innovative study, blending cutting-edge modelling techniques and data analysis from NASA’s Voyager spacecraft, revealed that four of Uranus’ largest moons—Ariel, Umbriel, Titania, and Oberon—could very well be hiding internal oceans beneath their frosty exteriors. This striking revelation challenges the long-held belief that only Titania, the heavyweight among the moons, could store enough warmth inside to sustain an ocean. The smaller moons had been deemed too small to hold onto the heat required.
Published in the Journal of Geophysical Research, this groundbreaking research casts a wider net, probing not just Uranus’ enigmatic moons but also the fundamental processes that create oceans in the most unexpected corners of our solar system. By poring over the findings from various NASA missions—including Galileo, Cassini, Dawn, and New Horizons—that have unveiled ocean worlds, scientists have gleaned invaluable insights into the geological and chemical makeup of icy celestial bodies, many of which share a similar size with the Uranian moons.
The study’s key breakthrough is the probable presence of chlorides and ammonia in the oceans of Uranus’ largest moons. Both substances are known to moonlight as antifreeze, potentially maintaining the subsurface oceans. Additionally, researchers stumbled upon potential heat sources lurking within the moons’ rocky mantles, which unleash hot liquid and could help an ocean stay warm, a scenario especially plausible for Titania and Oberon, where the oceans might even be toasty enough to potentially nurture life. As scientists delve deeper into the enigma of these moons and their beguiling oceans, they’ll be better equipped to plan future observations and devise suitable instruments to uncover the secrets of these icy worlds. For instance, the presence of ammonia and chlorides necessitates using a wavelength range encompassing both compounds for spectrometers. Moreover, this knowledge can be harnessed to design instruments capable of peering into the deep interiors for signs of liquid.
This captivating research not only broadens our comprehension of the Uranus system but also opens the doors to our solar system’s hidden recesses. The discovery of oceans in the most unlikely places expands the horizons for life beyond Earth and casts light on the astounding diversity and potential of the celestial bodies that populate our cosmic backyard.
Source: Greicius, T. (Ed.). (2023, May 4). New study of Uranus’ large moons shows 4 may hold water. NASA. https://www.nasa.gov/feature/jpl/new-study-of-uranus-large-moons-shows-4-may-hold-water
