Yes, we're finding new exoplanets all over the place, any of which could have conditions favorable to potential alien life. But it's not all about planets. A new international study has identified more than 100 giant planets that potentially host moons capable of supporting life.
The key to looking for exoplanets and exomoons is finding rocky terrain. And while large gas giants like Jupiter aren't rocky themselves, they often have rocky moons in their orbit. The Galilean moon Europa, for example, is often seen as the best chance for life inside the solar system.
“There are currently 175 known moons orbiting the eight planets in our solar system. While most of these moons orbit Saturn and Jupiter, which are outside the Sun’s habitable zone, that may not be the case in other solar systems. Including rocky exomoons in our search for life in space will greatly expand the places we can look.” says Stephen Kane, an associate professor of planetary astrophysics at University of California, Riverside (UCR) in a press release.
Working with scientists at the University of Southern Queensland in Australia, the team identified 121 giant planets that have orbits within the habitable zones of their stars. They used data from the Kepler Space Telescope, launched in 2009. One of NASA's most durable missions, the Kepler has survived several seeming death sentences in the vastness of space and the results mean thousands of more plants for scientists to pore over.
With their unmistakable size, each of these gas giants is believed to have multiple moons. From here, it's matter of further winnowing down the options.
"Now that we have created a database of the known giant planets in the habitable zone of their star, observations of the best candidates for hosting potential exomoons will be made to help refine the expected exomoon properties. Our follow-up studies will help inform future telescope design so that we can detect these moons, study their properties, and look for signs of life," says Michelle Hill, an undergraduate student at the University of Southern Queensland who worked on the paper.