While 55 Cancri e is far too hot to be habitable, researchers think it could provide a unique window for studying interactions between atmospheres, surfaces, and interiors of rocky planets, and perhaps provide insights into the early conditions of Earth, Venus, and Mars, which are thought to have been covered in magma oceans far in the past. “Ultimately, we want to understand what conditions make it possible for a rocky planet to sustain a gas-rich atmosphere: a key ingredient for a habitable planet,” said Hu.