Launched in October 2006, STEREO (Solar TErrestrial RElations Observatory) is the third mission in NASA's Solar Terrestrial Probes program (STP). It consists of two nearly identical observatories—one ahead of Earth in its orbit, the other trailing behind—that have traced the flow of energy and matter from the Sun to Earth. STEREO has revealed the 3-D structure of coronal mass ejections; violent eruptions of matter from the Sun that can disrupt satellites and power grids, and help researchers understand why they happen.

With this new pair of viewpoints, scientists can see the structure and evolution of solar storms as they blast from the Sun and move out through space. In fact, the probes have produced so many images that researchers are looking to citizen scientists to help them study all of the data that's being produced. This work will give astronauts an early warning if dangerous solar radiation is headed their way, and it may even lead to new scientific discoveries.

Solar Stormwatch—created by The Royal Observatory Greenwich, Rutherford Appleton Laboratory and Zooniverse—isn't just about classifying data. Citizen scientists can talk to other members on the project's forum, sign up for space weather forecast from Twitter, and learn about the latest discoveries on the project's blog. Volunteers can also see how solar storms affect Earth at the project's Flickr group Aurora chasers.