Transit of Mercury Square Wall Clock

A black and yellow fractal depiction of the Sun and the planet Mercury. When the planet Mercury passes between the Sun and the Earth it appears a small black dot on the Sun. This is called a "Transit of Mercury." Transits of Mercury with respect to Earth are much more frequent than transits of Venus, with about 13 or 14 per century, in part because Mercury is closer to the Sun and orbits it more rapidly. Transits of Mercury can happen in May or November. November transits occur at intervals of 7, 13, or 33 years. May transits only occur at intervals of 13 or 33 years. The last three transits occurred in 1999, 2003 and 2006 ; the next will occur in 2016.