Maybe spooks in the night ignite your Halloween frights, but a powerful solar storm more than a decade ago caused more than few scary consequences. One of the largest solar flares ever recorded at the time occurred the week of Halloween 2003. It erupted due to a series of enormous sunspots, one of which measured 13 (unlucky?) times the size of Earth. Sending you chills? Well, the sweats might be more like it, as the geomagnetic storm that followed caused disruptions and outages in more than half of Earth’s orbiting satellites as well as GPS and radio signals. On the upside, a beautiful aurora could be seen across many parts of North America.