Science Daily: Solar Explosion Tracked All the Way from the Sun to Earth.
ScienceDaily (Apr. 14, 2010) — An international group of solar and space scientists has built the most complete picture yet of the full impact of a large solar eruption, using instruments on the ground and in space to trace its journey from the Sun to Earth.
Dr Mario Bisi of Aberystwyth University presented the team's results, which include detailed images, on the 13th of April at the RAS National Astronomy Meeting in Glasgow.
Coronal mass ejections (CMEs) are giant eruptions of the Sun's atmosphere from its 'surface' which are ejected out into space. They are many times larger than Earth and typically contain over a billion tonnes of matter. CMEs travel away from the Sun at speeds of up to several million kilometres an hour (between 200 and 2000+ kilometres per second) and can impact on comets, asteroids, and planets -- including Earth.
Our planet is normally protected from CMEs by the terrestrial magnetic field, but the twisted magnetic fields carried by CMEs can break through this protective shield, causing particles to stream down over Earth's polar regions. They can also lead to displays of the northern and southern lights (aurora borealis and australis).