In the hunt to find a world beyond Earth that could harbor life, we’ve found over 4,500 exoplanets—planets that exist outside the solar system. A handful of these are thought to be potentially habitable, but that doesn’t mean they look like Earth. Many are what we might call “super-Earths,” which could be anywhere from two to 10 times more massive than our planet. But there’s a lot we don’t know about how the insides of these bigger planets work, or even whether they can support life of some kind.
A new study published in Science on Thursday, however, suggests super-Earths could be more friendly to life than smaller rocks like our planet. If that’s the case, alien hunters would spend their time more wisely scouring these heftier worlds for signs of life.
Extraterrestrial habitability is complex, but there are a few basic ingredients you absolutely need to host life—like the presence of actual water, and an atmosphere that blankets the planet and makes things feel warm and fuzzy. In order to maintain these things, however, a planet needs to produce a magnetic field that can protect it from its host star’s radiation. Earth has one that is constantly protecting us from getting bludgeoned by dangerous charged particles from the sun. Without this so-called magnetosphere, a planet’s atmosphere will hemorrhage away and the surface will quickly turn into a barren wasteland.