Mercury shows it's ass. Uranus is next.

So, something rare happened today. I was wondering why it's so rare.

http://www.space.com/32806-why-mercury-transit-of-sun-rare-event.html

Mercury transits occur just 13 times per century, on average. They're so rare because the innermost planet's orbit is inclined by about 7 degrees compared to that of Earth, so Mercury, the sun and our home planet just don't line up all that often.

So, it just doesn't happen as much that they line up.

Good job, nerds.