Our Sun is the closest star to us, by a factor of a quarter of a million. With modern equipment as inexpensive as $450, massive solar flares and prominences can be seen on its surface, changing in the space of minutes. Some solar physicists think that the next solar maximum (2010/2011) could be the most energetic ever studied, so being prepared for any major outburst is a sensible strategy.
The Sun follows a 11-year cycle of activity and, at every maximum, we see the disk sporting many large sunspots and having outbursts that, occasionally, can bring down entire national grid power systems here on Earth, as well as threatening the safety of astronauts and orbiting satellites. The most dramatic solar events are called coronal mass ejections or CMEs (see Figure
). These events were not observed until the 1970s, when orbiting satellite detectors first recorded them. They are the bigger brothers of the lower-energy, but more frequent, solar flares, often witnessed by...