| Term: | Coronal Mass Ejection |
| Definition: |
Not to be confused with the intense burst of light that is a solar flare, a CME is a cloud of magnetized solar material that erupts from the sun's atmosphere, the corona, into interplanetary space. CMEs do often occur at the same time as a flare, and scientists currently study how the two phenomena connect. At their largest, CMEs can contain 10 billion tons of matter, and they can move at speeds of a million miles an hour. Just after blowing into space, a CME cloud can grow as wide as 30 million miles across, 35 times the diameter of the sun. When a coronal mass ejection points toward Earth, it can take anywhere from one to three days to reach our atmosphere, where it can create a type of space weather known as a geomagnetic storm. |