By Ted Thurgur
It is well known that only two planets, Mercury and Venus, transit the Sun, as viewed from Earth because they are the two whose orbits around the Sun lie inside that of the Earth. This is clearly shown in the diagram (Image credit to Sky & Telescope) which shows the orbits of the planets and each of their movements during May 2016. The positions of the outer planets do not change significantly on this scale.
This was the second transit of Mercury that I have observed and attempted to photograph. My first attempt was on 2003 May 7th and was previously reported in Lyra. The transit of 2006 November 8th was not visible from the U.K.