Upper Michigan was greeted to a spectacular display of the Aurora Borealis, commonly known as the Northern Lights, Monday evening into early Tuesday. A solar eruption occurring during the early morning hours of Saturday, October 22nd reached Earth last night and created a weak geomagnetic storm. The Northern Lights activity was reportedly seen as far south as St. Louis and Wichita.
Information on current solar activity can be found at the Space Weather Prediction Center's (SWPC) website: http://www.swpc.noaa.gov/
The image below shows the solar eruption reaching Earth at approximately 9-10pm EDT Monday according to the SWPC's solar wind model. Earth is the green dot at the right of the image, the sun is the larger yellow dot at the center, and times are in GMT (EDT plus 4 hours).
Below are a couple of images of the Northern Lights as seen in Marquette (courtesy of a Marquette NWS employee).