It's also Pale Blue Dot day! For those that haven't seen it before, it's a photo of Earth taken on the 14th of February 1990 from well beyond the orbit of Neptune. Earth is that single blue pixel.
Wow. Puts into perspective how big space is. “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” - Dogulas Adams.