There's a little black spot on the sun today.

Did you watch Venus cross the Sun? The Transit of Venus which occurred yesterday was the last one this century. "The next transits of Venus will be in December 2117 and December 2125."
That's right, if you missed it, you have to wait 105 years for the next one. It is kinda cool to watch the little black dot of Venus slowly move across the sun, but the coolest part about the transit is that not only is it one of the rarest predictable phenomenon, but it was first predicted in 1627 by Johannes Kepler who calculated the 1631 event. Unfortunately, Kepler died in 1630 so he never knew his prediction was correct.