Following on from yesterday’s solar coronal mass ejection post, some images of sunspots and ultraviolet light, comparing the Sun’s surface conditions from last week back to July 2000.

Another possible threat to Earth and life thereon, a coronal mass ejection, or a fireball like spewing of plasma from the Sun.

It is hard to conceive of the sun wiping out a large amount of our hard-earned progress. Nevertheless, it is possible. The surface of the sun is a roiling mass of plasma – charged high-energy particles – some of which escape the surface and travel through space as the solar wind. From time to time, that wind carries a billion-tonne glob of plasma, a fireball known as a coronal mass ejection (see “When hell comes to Earth”). If one should hit the Earth’s magnetic shield, the result could be truly devastating.

A similar type of situation was the subject of a science-fiction novel, Sunstorm, co-written by Arthur C. Clarke and Stephan Baxter in 2005, which saw the construction of a giant shield in space in an effort to protect Earth from a solar plasma outburst.