<a href="http://www.boulder.swri.edu/~deforest/trace_april2002_xflare.mpg">
Here</a>'s a movie I just finished making from TRACE archive data. It's a solar flare that happened on 21-April-2002. You can see images of it on the <a href="http://vestige.lmsal.com/TRACE">TRACE website</a> or the <a href="http://sohowww.nascom.nasa.gov">SOHO site</a>.
<p>TRACE is a small satellite in low Earth orbit; SOHO is a large observatory stationed at L-1. Because TRACE is newer it has about 5x better resolution than the instruments aboard SOHO -- but it will likely re-enter Earth's atmosphere in a couple of years.
<p>The movie has been rotated so that solar west is UP (that image was rotated the same way), and has been resampled to 2 minutes per frame, for five hours of original time. In both the still image and the movie you're seeing extreme ultraviolet light emitted by Fe 11+ -- iron that's stripped of 11 of its electrons by the intense heat -- at about 2,000,000 Centigrade.
<p>The big bright slinky thing is about 10-15 Earth diameters tall.
<p>The amount of energy released is equivalent to covering the entire surface of the Earth more than 10 meters deep in TNT and setting it all off.
<p>The last time one of these things pointed in the general direction of Earth (last October), it caused aurorae that stretched as far south as San Diego.