The planet Mercury transited across the face of the sun on Monday. From earth only the two innermost planets can transit the sun.
It is that little black dot at “nine o’clock” on the face of the sun. The other marks are sunspots.
Transits of Venus are very rare and come in pairs with the next in 2117. Mercury’s transits occur in intervals of seven, 13 and 33 years.
We might see the start of the next one from Shetland on the afternoon of 11th November 2019. The next transit we have a chance to see start to finish is in May 2049.