Early Thursday morning, solar observers watched as a dark spot on the sun erupted with an enormous flash of light, causing the biggest solar flare of 2013. Solar flares themselves don't last long, but this one was powerful enough to cause a bubble of solar material called a CME (coronal mass ejection) to come bursting off the sun. Up to billions of tons of that solar material is now hurtling through space at the mind-bending speed of more than 600 miles per second, and it is heading directly toward Earth.
While a mass of solar material zooming toward Earth sounds kind of frightening, there's not much to worry about. CMEs can occasionally affect the electronic systems of satellites or the power grid here on the ground, but our atmosphere will protect us from any harmful radiation associated with the initial flare or the CME. Plus, there's a major upside to these Earth-bound CMEs for sky watchers. When a CME interacts with the Earth's magnetosphere, it can cause geomagnetic storms and enhanced auroras that could be visible as far south as Michigan and New York.