Friday, December 15, 2006

The Beauty of Solar Burps


Part of my job is working with a solar telescope and talking about the sun with school kids, so I tend to keep up with solar activity. The sun has a roughly 11-year cycle where it goes from essentially no activity (meaning sunspots, flares, CMEs, etc.) to a bunch of activity and then back down to none. Right now we're at about the bottom, although activity is starting to creep back up and this week a large sunspot has produced several flares and CMEs. The cool thing about these eruptions is that when that energy impacts the Earth's atmosphere, it produces aurorae. Folks in more northerly areas are reporting and photographing some beautiful Northern Lights this week, and some have submitted the photos to the aurora gallery at one of my favorite websites, spaceweather.com.

Being in Texas, it is rare for us to see aurorae, but with particularly large explosions they can be seen. They are usually a red glow on the northern horizon (in my experience), not the rich variety of colors seen at more northern latitudes. Someday I'm going to be father north at the right time to see some!

The little movie at top is from the SOHO spacecraft, which monitors for solar activity everyday. This is the flare from December 14th and is at 195 Angstroms (the sun doesn't actually look green at that wavelength, it's just colored that way in the computer... that wavelength is in the ultraviolet and cannot be seen with the human eye).

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