Solar coronal mass ejection (CME) is a massive explosive event, which ejects plasma, or solar wind or open single-pole magnetic fields ejects plasma from the corona into space. Coronal mass ejection is often associated with other solar activities, mainly with solar flares. Most of them come from active regions of the solar surface, where the sunspots are associated with solar flares during solar maximum, but can also occur during the solar minimum.
When solar winds arrive near the Earth they crash into the magnetic field and they can cause geomagnetic storms. Charged particles in the field turning and follow his lines toward the planet poles. They collide in atmosphere with atoms of nitrogen and oxygen and create a miniature neon lights.
Coronal mass ejection is certainly a most violent physical process in the whole solar system.