The big solar storm of 2012 was one for the record books.
On July 23, 2012, a massive cloud of solar material erupted off the sun's right side, zooming out into space and passing one of NASA's twin STEREO spacecraft along the way. Scientists clocked this giant cloud, known as a coronal mass ejection, or CME, as traveling over 1,800 miles per second as it left the sun. This was the fastest CME ever observed by STEREO. Luckily, it was moving in a direction safely away from Earth. The harshest space weather can have strong effects on the magnetic system surrounding our planet, which in turn can affect satellites and interrupt GPS and radio communications. At its worst, rapidly changing magnetic field lines around Earth can induce electric surges in the power utility grids on the ground. Using observations from multiple NASA spacecraft, scientists reconstructed the full shape and expansion of the CME in a computer model. They learned that an earlier, smaller CME helped clear the path for the larger event, thus contributing to its unusual speed. Watch the video to learn more.