On May 7th, 2003 Mercury made a transit over the solar disc. First contact happened at 05:12:56 GMT (Universal Time), and last contact at 10:31:46 GMT. The greatest point happened at 07:52:23 GMT, for reference see the drawing below (Nasa bulletin).
Solar disk on May 7th, 2003.
This photo is the same as the one above except for the transit grid.
Closer view of Mercury,