A Rare Transit of Mercury - Mercury on Sun
Closeup and enhanced version of full sun photograph - I like this one best, will have to wait till 2016 to do a better one. Click on "all sizes"
Transits of Mercury don't happen very often, about 12 more this century. The last was on May 7, 2003, and the next doesn't come until May 9, 2016 - early in the morning for viewing from my place.
This image is on Wikimedia
Caught an instant of good seeing, Mercury is <10 arc seconds across.
Date 11/8/06 Time 11:41:12 pst
ExposureTime: 1/1600 seconds
Lens 1440mm, at f18, off axis mirror with solar filter
Camera: Canon Digital Rebel with improved software