A solar movie-making program produced by scientists from NASA and the European Space Agency just hit a major milestone: its millionth movie. The Helioviewer project - consisting of an online tool at Helioviewer.org and its sister application JHelioviewer -- has been available since 2009. Helioviewer is the brainchild of Jack Ireland, a solar scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., who wanted a way to look at vast arrays of solar data through a single interface.

"There's one sun, but many different solar observatories," said Ireland. "They're all looking at the same thing, and I thought it should be possible to overlay that information together. That way you could get the images you were looking for without having to go to multiple websites."

Solar scientists are lucky to have a vast array of telescopes - both on the ground and in space - observing different aspects of the sun. Each is tailored to offer details on a particular region, a particular process, or a particular temperature of solar material. Indeed, some observatories offer multiple views: NASA's Solar Dynamics Observatory provides 13 different views all by itself.

Many research projects require looking at how a given event on the sun appears and develops through a variety of these instruments, together forming a complete image of what's happening. But with each instrument collecting different data and relying on different software, combining the imagery is not straightforward.

In 2004, Ireland sought an easy, user-friendly platform on which to layer these images. He received a grant to explore the idea and thus Helioviewer was born. In 2007, Daniel Mueller of the European Space Agency joined him to develop the companion application JHelioviewer. Helioviewer.org can be accessed exclusively online, while JHelioviewer is a program that runs locally on a computer.

The Helioviewer project does more than allow scientists to watch the dance of solar events, it allows everyone access to these gorgeous views of the sun. Indeed, with the many eyes of citizen scientists accessing the program, images of interesting events on the sun are more prolific than ever. Such movies are made constantly, and in late April 2013, one user made the project's millionth movie.

"The 1 millionth movie shows a thin puff of material flying up off the sun," said Ireland. "But it turns out that evolved into a coronal mass ejection that many people took notice of. Scientists attempt to collect all the events into a single shared database, but as far as I know the only record of this little puff is the video that a Helioviewer.org user made."

In addition to an improved way to look at solar imagery, Helioviewer also sports an online space for sun watchers to gather and talk, thus, becoming a prime example of crowdsourcing. At 6 a.m. EDT on June 7, 2011, for example, Ireland checked recent Helioviewer movies and conversations. An anonymous early bird to the site had already posted a movie of a gigantic fountain of solar material that had only just exploded off of the sun.

"It was spectacular," said Ireland. "Unlike anything I had ever seen before."

The movie showed a giant cloud of solar particles mushrooming up and falling back down to cover what appeared to be almost half of the surface of the sun. Thanks to his contacts on Helioviewer, Ireland was one of the first people to see it and alert his colleagues.

Ireland - and Keith Hughitt, who joined the Helioviewer team at Goddard in 2008 - attribute Helioviewer's popularity to its user-friendliness, something they worked hard to achieve. Accessing the fire hose of solar data is not always quick or easy, and is only possible for Helioviewer due to improvements in modern computer imaging. The builders made use of technology pioneered in such things as Google maps to break up larger images into smaller tiles.

"The Solar Dynamics Observatory sends down a terabyte of data per day," said Hughitt.

"That would be an overwhelming amount of information for a computer to download every time you wanted to see a movie. We set up Helioviewer to only display the part of an image you are interested in at the time. That makes it possible for this data to be accessible over a web browser."

Helioviewer currently offers images from as early as 1991, using such sources as the Solar Dynamics Observatory, the joint ESA/NASA Solar and Heliospheric Observatory, NASA's Solar Terrestrial Relations Observatory, the Japan Aerospace Exploration Agency's Yohkoh observatory, and ESA's PROBA-2 satellite. They are working to include additional information from JAXA's Hinode mission, NASA's Reuven Ramaty High Energy Solar Spectroscopic Imager, and NASA's Transition Region and Coronal Explorer. The team also has plans to include results from the Heliophysics Event Knowledgebase, a shared scientists' catalogue that keeps track of features and events on the sun.