Coronal Mass Ejection

sun · space weather · plasma · solar storms

A massive burst. A coronal mass ejection (CME) is when a huge cloud of plasma, which is super-hot gas made of charged particles, shoots out from the Sun's corona (the Sun's outermost layer) into space. One CME can carry billions of tons of material traveling millions of miles per hour.

Often comes with flares. CMEs usually happen together with solar flares, which are sudden bright explosions on the Sun's surface. Scientists know they're connected, but they're still figuring out exactly how one causes the other.

Can affect Earth. When a CME reaches our planet, it can create amazing auroras (the northern and southern lights) in the sky. Super powerful CMEs can sometimes mess with power grids and satellites, though Earth's magnetic shield protects us from the worst effects.

Made of plasma. Plasma is the fourth state of matter (after solid, liquid, and gas) and it's made of electrons and ions floating around separately. The plasma in a CME is so hot and energetic that it creates its own magnetic fields as it travels through space.

Hard to predict. Scientists can spot CMEs happening, but predicting exactly when and where they'll occur is still tricky. Space agencies constantly watch the Sun to warn people on Earth if a big one is heading our way.