‘Bizarre’ Moon Around Uranus Could Suddenly Host Life — What To Know

A small moon orbiting Uranus called Miranda may have an ocean below its icy crust, suggests a new study of archive images taken 38 years ago. If it's true, Miranda has the potential for life alongside other ocean worlds in the solar system, such as Europa at Jupiter and Enceladus at Saturn.

According to NASA , the seventh planet from the sun has 28 moons, but five major moons — Miranda, Ariel, Umbriel, Titania and Oberon. All are named after characters from William Shakespeare and Alexander Pope's works rather than being from Greek or Roman mythology, as is traditional in planetary science.

Miranda has a diameter of just 290 miles (470 kilometers), but it could be about to become the new darling of astrobiologists and planetary scientists searching for life in the solar system.

Uranus Moon: Virtually Unexplored

Uranus is virtually unexplored. It was visited for just 45 hours by NASA's Voyager 2 in 1986 during its "Grand Tour" of the solar system's four giant planets. Voyager 2 also took images of the five largest moons of Uranus.

During its brief flyby of Miranda, Voyager 2 imaged only the tiny moon's southern hemisphere. It found an ancient cratered terrain pockmarked with craters, with smooth floors reminiscent of Earth's moon and Enceladus.

Uranus Moon: Tidal Forces

The new study, published in the Planetary Science Journal in October, revisited Voyager 2's images and claims that Miranda's geology results from tidal forces from neighboring moons. Similar to the pull of the Earth's tides, gravitational tugs from nearby moons deform Miranda and create friction and heat that keep its interior warm, also creating stresses that crack the icy surface, making the moon a rich tapestry of geologic features.

To come to that conclusion, a team of scientists figured out what the Miranda's interior must have been like to produce the surface features seen by Voyager 2. The best match was a vast ocean, at least 62 miles (100 kilometers) deep, beneath the moon's 19 miles (30 kilometers) thick icy crust.

That ocean must have existed 100-500 million years ago, argue the scientists, and it may still be there.

Uranus Moon: 'Exciting And Bizarre'

The scientists suspect that Miranda's modern-day ocean, if it exists, is relatively thin. However, the fact that an ocean world could exist so far from the sun is a shock to planetary scientists. "To find evidence of an ocean inside a small object like Miranda is incredibly surprising," said Tom Nordheim, a planetary scientist at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, a study co-author, and the principal investigator on the project that funded the study. "It helps build on the story that some of these moons at Uranus may be really interesting — that there may be several ocean worlds around one of the most distant planets in our solar system, which is both exciting and bizarre."

With as suspected ocean on Miranda, planetary scientists now think Ariel, Umbriel, Titania and Oberon could also have subterranean oceans.

Uranus Moon: NASA Mission?

Should NASA send a mission to Uranus and its moons? After all, if Miranda has, or ever had an ocean, it instantly becomes a target for studying habitability and life. For now, that's speculation. "We won't know for sure that it even has an ocean until we go back and collect more data," said Nordheim. "We're squeezing the last bit of science we can from Voyager 2's images. For now, we're excited by the possibilities and eager to return to study Uranus and its potential ocean moons in depth."

A paper published in 2021 proposed NASA send a Uranus orbiter on a flagship mission to see if the five largest of its 27 moons might be ocean worlds.

If NASA is to do so, it will need to hurry. A rare planetary alignment of Neptune, Uranus and Jupiter will soon provide a rare window to send a spacecraft on a "slingshot" via Jupiter Uranus on a journey that would be shortened to 11 years. However, any spacecraft would need to leave Earth by 2034.

Wishing you clear skies and wide eyes.