http://www.newscientist.com/blog/technology/2008/03/do-we-need-cosmic-ray-alerts-for.html

Should every computer chip have a cosmic ray detector?
How can distant supernovae, black holes and other cosmic events cause a desktop computer to crash?

Tom Simonite, Newscientist.com
Friday, March 07, 2008

The answer is that they produce cosmic rays, which produce high energy particles in the atmosphere that can occasionally hit RAM chips. The moving particles trail electrons, which can infiltrate chips' circuits and cause errors.

That's why computer chip giant Intel was in December awarded a US patent for the idea of building cosmic ray detectors into every chip