It was about 10 years since I saw the last Transit of Mercury across the face of sun. The last time I had a lot of time to get set up and practice my exposures on the sun. This year I was working and was only able to get the last hour of this rare celestial event.
Transits of Mercury occur in May or November. The last four transits occurred in 1999, 2003, 2006, and May 9, 2016. The next will occur on November 11, 2019, and then on November 13, 2032.
Here an image I took with my Coronado 40mm Solar Hydrogen Alpha Telescope. Yes, Mercury is that small black dot in the center of the image.