New research prompts rethink on chances of life on Uranus moons

The planet Uranus and its five largest moons may not be the dead and sterile worlds that scientists have long believed.

Instead, they may have oceans, and moons may even be capable of supporting life, scientists say.

Most of what we know about them was gathered by NASA's Voyager 2 spacecraft, which visited them nearly 40 years ago.

But new analysis shows that Voyager's visit coincided with a powerful solar storm that led to misconceptions about what the Uranus system is really like.

Uranus is a beautiful world surrounded by icy rings located on the outskirts of our solar system. This is one of the coldest planets. It's also tilted on its side compared to all the other worlds – as if it's been tipped over – which makes it perhaps the strangest.

We first saw it up close in 1986, when Voyager 2 flew by and sent back sensational photos of the planet and its five main moons.

But what surprised scientists even more was data sent back by Voyager 2 indicating that the Uranus system was even stranger than they thought.

Measurements from the spacecraft's instruments showed that the planets and moons were inactive, unlike other moons in the outer solar system. They also showed that Uranus's protective magnetic field was strangely distorted. It was crushed and pushed away from the Sun.

The planet's magnetic field traps any gases and other materials coming from the planet and its moons. This could be the oceans or geological activity. Voyager 2 found nothing, suggesting that Uranus and its five largest moons were sterile and inactive.

This came as a huge surprise because it was not like the other planets in the solar system and their moons.

But a new analysis has solved a decades-long mystery. This shows that Voyager 2 flew by on a bad day.

A new study shows that when Voyager 2 flew past Uranus, the Sun was raging, creating a powerful solar wind that could blow away material and temporarily distort the magnetic field.

So, according to Dr. William Dunn of University College London, for 40 years we had a misconception about what Uranus and its five largest moons typically look like.

“These results show that the Uranian system may be much more exciting than previously thought. There may be moons that may have the conditions necessary for life, they may have oceans below the surface that may be teeming with fish!”

Linda Spilker was a young scientist working on the Voyager program when the Uranus data arrived. She is currently still working as a mission scientist for the Voyager mission. She said she was pleased to hear about the new results that were published in the journal Nature Astronomy.

“The results are amazing and I'm really excited to see that the Uranian system has the potential for life,” she told BBC News.

“I'm also very pleased that so much is being done with the Voyager data. It's amazing that scientists are looking back at the data we collected in 1986 and finding new results and new discoveries.”

Dr Affelia Wibisono of the Dublin Institute for Advanced Study, who is independent of the research team, called the results “very exciting”.

“This shows how important it is to look back at old data, because sometimes there is something new behind it that can help us design the next generation of space exploration missions.”

That's exactly what NASA is doing, partly as a result of new research.

It's been nearly 40 years since Voyager 2 last flew past the icy world and its moons. NASA has plans to launch a new mission, the Uranus Orbiter and Probe, to return for a more thorough study in 10 years.

According to NASA's Dr. Jamie Jasinski, whose idea was to re-examine Voyager 2's data, the mission will need to take its findings into account when developing its instruments and planning its science.

“Some of the instruments for the future spacecraft are being designed largely using ideas that we learned from Voyager 2 when it flew past the system and experienced an anomalous event. So we need to rethink how exactly we are going to design instruments for a new mission so that we can best capture the science needed to make discoveries.”

NASA's probe to Uranus is expected to arrive by 2045, when scientists hope to discover whether these vast icy moons, once thought to be dead worlds, might have the potential to be home to life.