Summary: As night fell across North America on Tuesday, April 17th, an interplanetary shock wave swept past Earth and triggered a strong (G3-category) geomagnetic storm. The shock wave was generated on Easter Sunday (April 15th) when a powerful X14-class solar flare exploded near sunspot 9415. The record-setting explosion hurled a coronal mass ejection into space, but not directly toward our planet. Today's disturbance was probably not the CME itself, but rather a shock wave created by the CME as it rapidly plowed through the interplanetary medium.

Unless otherwise stated, all images are copyrighted by the photographers.

	Photographer, Location	Images	Comments
	Duane Clausen, Menominee , MI	#1	D. Clausen: "These twisted ribbons of green and red appeared directly overhead for almost 20 minutes." Photo details: 28mm lens , f2.8, 25 seconds. April 18, 2001
	Mark Simpson, Calgary, Alberta, Canada	#1, #2, #3, more	M. Simpson: "These auroras were the brightest I've ever seen. At midnight it was lighting up the back yard in spite of our urban light pollution." Photo details: Pentax LX SLR Camera. Film: Fuji Superia ASA 800. 28mm lens, f2.8 April 17-18, 2001
	Ron Giachetti, Sacheen Lake, 50 miles north of Spokane, WA	#1, #2, #3, #4, #5	Photo details: digital Toshiba PDR-M70 with 30 and 60 second exposures. April 17-18, 2001
	Lyndon Anderson, 15 miles north of Bismarck, ND	#1, #2	L. Anderson: "The lights were moderate in brightness, mostly a diffuse glow with some beams that went directly overhead. It was very nice." Photo details: Fuji Superia 800 film. April 17, 2001
	Garth Arsenault, Charlottetown, Prince Edward Island, Canada	#1, #2, #3, #4, #5, #6, more	G. Arsenault captured these pictures from the Prince Edward Island National Park at the Anne of Green Gables House and at Cavendish Beach. April 17-18, 2001
	Stan Richard, near Collins, Iowa, USA	#1, #2, #3, #4, #5, more	S. Richard: "The one with the school in the foreground was shot under light polluted suburban skies, I saw this display right through the bright street lights!" Photo details: 28mm lens at f/2.5, 20-30 secs using Kodak Supra 800 film April 17, 2001
	William Hitchens, the lower shore of Maryland, USA	#1, #2, #3	Photo Details: Petri Racer 45mm f/1.8 lens, Kodak MAX 400, 10 to 20 sec. exposures. April 18, 2001 (0230 UT)