Space weather can affect satellites in orbit, trigger geomagnetic storms on Earth and interfere with ground infrastructure. We need to understand it better, and the best way to do that is look at where it comes from.

The Sun’s corona, its upper atmospheric layer, gives rise to the solar wind and is where coronal mass ejections are spawned: massive outward explosions of charged plasma. ESA’s Proba-3 double-satellite mission will use formation flying to open up sustained coronal views. Mimicking a total solar eclipse, one satellite will block out the fiery face of the Sun by casting a shadow onto the other. This means the mission can observe the fine-scale structures of the corona without being blinded by the Sun’s glare.