Uranus’ moons Titania and Oberon may have oceans warm enough to support life

If there is extraterrestrial life in our solar system, experts have long thought it could be hiding beneath the surface of Mars, in the clouds of Venus, or in the icy oceans of the moons of Jupiter and Saturn.

But a new study points to another possibility.

NASA scientists say Uranus’ moons Titania and Oberon may also have oceans warm enough to support life, suggesting we should look there too in our hunt for aliens close to home.

They made their discovery after reanalyzing data from Voyager 2’s close flybys of Uranus in the 1980s, as well as using computer models to look for signs of water on five of the planet’s largest icy moons.

It is the first study to determine how the make-up and structure of the interior has evolved on Ariel, Umbriel, Titania, Oberon and Miranda.

What they found is that four of them — all except Miranda, Uranus’ innermost and fifth-largest moons — likely contain an ocean between their cores and icy crusts.

These bodies of water can be so vast that each is tens of miles deep, NASA researchers at the Jet Propulsion Laboratory in Southern California revealed.

They came to their conclusion after determining that Ariel, Umbriel, Titania, and Oberon are probably sufficiently insulated to retain the internal heat that would be required to house an ocean.

In fact, on Titania and Oberon, these oceans may even be warm enough to support possible extraterrestrial life, the scientists said.

This was supported by the discovery of what could be a potential source of heat in the moons’ rocky mantles, which release hot liquid and would help an ocean maintain a warm environment.

In all, Uranus has at least 27 moons orbiting it, the four largest of which range from Ariel – which is 720 miles (1,160 km) in diameter – to Titania, which is 980 miles (1,580 km) in diameter.

Experts have long believed that given its size, the latter would be most likely to retain internal heat due to the heat created by radioactive decay.

By comparison, here on Earth, 50 percent of the heat our planet gives off is generated by the radioactive decay of elements like uranium and thorium.

It was previously thought that Uranus’ other large moons were too small to retain the heat needed to keep a subsurface ocean from freezing, but the new research challenges this belief.

One of the other reasons scientists assumed this was the case is that the heat created by Uranus’ gravitational pull is only a minor source of heat.

In other planets, such as Jupiter and Saturn, a gravitational phenomenon known as tidal heating helps to heat their moons significantly.

This a gravitational tug of war between the moons and the planets themselves causes the natural satellites to stretch and compress enough to heat them up.

It is thought that this could help warm the moons’ waters and create possible conditions for life.

“When it comes to small bodies — dwarf planets and moons — planetary scientists have previously found evidence of oceans in several unlikely places, including the dwarf planets Ceres and Pluto, and Saturn’s moon Mimas,” said the study’s lead author, Julie Castillo-Rogez. , from NASA’s Jet Propulsion Laboratory.

‘So there are mechanisms at play that we don’t fully understand.

“This paper explores what that might be and how they are relevant to the many bodies in the solar system that may be rich in water but have limited internal heat.”

By studying the composition of these oceans, scientists can also learn about materials that can also be found on the icy surfaces of the moons, such as if subsurface substances have been pushed up by geological activity.

For example, at least one of Uranus’ largest moons — Ariel — has material that could have come from icy volcanoes that erupted onto its surface relatively recently.

There are also what appear to be recent surface features on Miranda that suggest it may have retained enough heat to have an ocean for a period of time, though it probably wasn’t very long.

Thermal modeling shows that the moon is losing heat too quickly and is now probably frozen.

It’s important to dig into what lies beneath and on the surface of these moons, as it will help scientists prepare for future missions to the seventh planet from the sun.

For example, they need to know which scientific instruments are most convenient to attach to a spacecraft or probe that yield the most informative findings.

“We need to develop new models for different assumptions about the origin of the moons to guide planning for future observations,” Castillo-Rogez added.

The researchers built computer models using data from NASA’s Galileo, Cassini, Dawn and New Horizons spacecraft, each of which discovered ocean worlds.

This information included details about the chemistry and geology of Saturn’s moon Enceladus, Pluto and its moons Charon and Ceres – all icy bodies about the same size as the moons of Uranus.

The modeling not only provided insight into the porous surfaces of the worlds, but also revealed a high concentration of chlorides and ammonia below the surface.

This is important because ammonia has antifreeze properties, while salt would also prevent the water on the icy moons from freezing.

NASA scientists now hope to continue developing models of the Uranian system in preparation for possible future missions to explore the distant ice world and its moons.

The research has been published in the Journal of Geophysical Research.