When studying exoplanets, scientists often judge habitability by the possibility of liquid water on the planet’s surface. But there is more to Earth’s habitability than water. The liquid iron dynamo within our planet is critical for life here because it generates magnetic fields that protect the planet from harmful solar radiation. It’s been difficult to predict what the interiors of a bigger and more massive planet like a super-Earth would look like, but a recent study changes that.
Researchers at the National Ignition Facility used its high-powered lasers to subject liquid iron to conditions similar to those expected in a super-Earth’s core, including pressures as high as ~1000 GPa. That’s more than 3 times higher than pressures at the boundary where Earth’s liquid iron meets its solid core. Based on their findings, the team concluded that super-Earths likely have a similar interior structure to our planet, with a solid iron-heavy core surrounded by churning liquid iron capable of generating a protective magnetosphere. (Image credit: NASA; research credit: R. Kraus et al.; via Science)