On the night of August 11-12, 2000, we went out expecting to see the Perseid meteor shower. We did see some nice meteors and fireballs, but the unexpectedly brilliant auroral display stole the show. Here are some pictures from that night. All images were shot with Fuji 400 ASA and a 50mm lens at f/2.4. All exposures were between 20 and 60 seconds. Photoshop used to enhance brightness and contrast of the scans. Observing site: Indian Lake Park, 11 miles NW of Madison, WI.
Aurora originate high above the surface of the earth, far above normal cloud layers. Charged particle emissions from the sun are channeled by earth's magnetic field lines. Where they enter the upper atmosphere, they interact with atmospheric oxygen and nitrogen, at altitudes from about 60 miles up to about 200 miles. During this interaction a part of the energy of the collisions transforms to visible light. For more information on aurorae, click here.
For more pictures of this event, click here. "Corona" effect at the zenith Image Taurus with Jupiter and Saturn Image Lovely green hues Image A bit of red or deep purple Image Beautiful streamers in Pegasus Image Dramatic green "curtain" above northern horizon Image
More aurora links:
Northern Lights - primarily oriented toward the science of aurorae but lots of great pictures too.
Dick Hutchinson - tons of photographs and great stories from an aurora watcher
My article on the August 11-12 aurora display.
John Rummel's Site Index