A Coronal Mass Ejection (CME)
A CME is a cloud of hot magnetized
gas, weighing billions of tons, which
is launched from the Sun at a speed
up to millions of miles per hour. The
CME shown in the sequence at the
right was launched over an 8-hour
period in 1996.
CMEs are caused by the breaking
apart of magnetic forces. These
occur almost every day, but most go
off in other directions, not toward
Earth.