A huge solar flare temporarily knocked out GPS communications
On the morning of 6 September the sun let out two pretty sizeable burps of radiation. Both were considered X-class -- the strongest type of solar flare -- with one of them proving to be the most powerful since 2005. If a solar flare is directed at Earth, which these ones were, it can generate a radiation storm that interferes with radio and GPS signals. The biggest flare ever recorded, in 2003, was so strong it even knocked out NASA's solar measurement equipment.