2133

"A very rare event in astronomy is the passage of one planet in front of another (occultation), as seen from Earth. Mercury and Venus occult each other every few centuries, and the event of May 28, 1737 is the only one historically observed, having been seen by John Bevis at the Royal Greenwich Observatory.[23] The next occultation of Mercury by Venus will be in 2133."

http://en.wikipedia.org/wiki/1737

the world has gone green and the plants are singing: