Late last week a strong solar flare may have knocked out a stabilizer on the ISS. The flare was so strong it sent ESA scrambling to diagnose problems on several of its missions. Flares create blasts of radiation that hit earth in a few minutes, then coronal mass ejection (CME) can hit the planet over several days. These strike the ionosphere, which protects the planet from most of the harmful results, sometimes disrupting satellite communication, creating a geomagnetic storm (and providing some pretty auroras).