Skip to main content

In the search for extraterrestrial life, we should look to exomoons

Artist’s impression of a potentially habitable exomoon orbiting a giant planet.

The search for life outside of our planet has a new target: exomoons. Traditionally scientists have looked to other planets for signs of life, but a new study by an astrophysicist from the University of Lincoln, U.K., suggests we may be more successful if we started looking at moons as well.

Dr. Phil Sutton looked for exomoons orbiting the planet J1407b, a gas giant which is one of the first planets with a large ring system to be discovered outside our Solar System. Called a “super-Saturn,” the 16 million-year-old planet is located 434 light-years away. The planet’s vast system of rings means a good possibility that moons could be found in orbit around it.

Related Videos

This is important because relatively few exoplanets have been found in the “habitable zone” around stars, where they are close enough to their stars for liquid water to be present on their surface, but far enough away that the water doesn’t vaporize. It is generally believed that liquid water is an essential component for the development of life, making exoplanets in the habitable zone promising targets for investigation. Because there are few of these planets, we could instead look at moons, which Sutton believes are more likely to host liquid water.

“These moons can be internally heated by the gravitational pull of the planet they orbit, which can lead to them having liquid water well outside the normal narrow habitable zone for planets that we are currently trying to find Earth-like planets in,” Sutton explained to Sci News. “I believe that if we can find them, moons offer a more promising avenue to finding extraterrestrial life.”

In his study of J1407b, Sutton modeled the rings around the planet, which are 200 times the size of those around Saturn. In the case of Saturn, there are gaps in the rings which are caused by the presence of nearby moons. But in the case of J1407b, Sutton found that if he added a moon to the model at various distances from the planet, it did not explain the gaps observed in the rings.

The study will be published in the journal Monthly Notices of the Astronomical Society and is available to view on pre-publication archive arXiv.

Editors' Recommendations

Whose name should we etch on the Mars 2020 rover? NASA wants a vote
get your name on mars 2020 rover mars2020 sendname home

As much talk as there is about Mars colonization, it’s still going to be a good few years before humans land on the Red Planet. But that doesn’t mean that your name can’t be among the first to make its way to the Martian landscape -- and it won’t even require you to train as an astronaut to do so. That’s because NASA opened up a new public outreach initiative to let individuals send their names to Mars, as an engraving on a silicon chip sent with the space agency’s next Mars rover, due to launch in 2020 and touch down in February 2021.

"As we get ready to launch this historic Mars mission, we want everyone to share in this journey of exploration," Thomas Zurbuchen, an associate administrator for NASA's Science Mission Directorate (SMD), said in a statement. "It's an exciting time for NASA, as we embark on this voyage to answer profound questions about our neighboring planet, and even the origins of life itself."

Read more
Trip to Neptune’s moon, Triton, could inform search for extraterrestrial life
nasa proposed mission triton 529 pia00317 modest

Global color mosaic of Triton, taken in 1989 by Voyager 2 during its flyby of the Neptune system. NASA/JPL/USGS

NASA has proposed sending a spacecraft to Neptune in order to study its largest moon, Triton, up close. Representative's from NASA's Jet Propulsion Lab (JPL) announced the plan at a the Lunar and Planetary Science Conference in Texas last week.

Read more
Scientists pinpoint exoplanets where life could bloom like here on Earth

A few decades ago, the search for extraterrestrial life was a fringe science. (Remember Jodie Foster’s eccentric and ostracized character in Contact?) Today, it’s captured the interest and imagination of astronomers and laymen alike.

If and when we do discover alien life, there is a good chance it will have taken hold on an exoplanet -- that is, a planet outside our own solar system. With improved instruments, scientists have made some tantalizing discoveries over the past year, identifying a handful of exoplanets that may harbor life, and instigating speculation about where to look.

Read more