The STEREO Ahead spacecraft caught two back-to-back solar eruptions aimed at Earth on January 23, 2012. This movie shows both the first solar eruption, followed soon after by a bigger faster eruption and associated flare, as seen by the EUVI telescope in the hot Iron emission line at 195 Angstroms (green), by the COR1 coronagraph in visible light (blue), and by the COR2 coronagraph (red). The interaction between the two eruptions, as the second faster one plows into the first slower one, was responsible for a large particle storm at Earth for several days following the eruption. The eruptions themselves reached Earth two days later on January 24, creating beautiful aurora displays.
credit: NASA / STEREO