The more I think about Monday’s transit of Mercury, which you can read about all over the Internet, including a couple of posts down, the more I think about how incredible a thing is going on here. Most people, including me, probably won’t be able to see it, even though the Sun will be up the whole time. The Sun’s just too bright, and Mercury’s just too small to be seen without special tools. That’s okay, though. There’s something incredible knowing that’s it’s happening anyway; just like it’s amazing to know a friend is becoming a parent, or getting a great new job, or just having a terrific dinner without you. It’s a real chance to get some great perspective on the size of the solar system, and on our place in it.
Mercury’s only 3000 miles across and is 50 million miles away, while the Sun is over 800,000 miles across, and nearly another 40 million miles farther. Yet, still, from where we sit, it’s going to take over seven hours for Mercury to creep across the Sun; silently and invisibly to most of us while we spend our day rushing around, missing deadlines, and getting cut off in traffic. The funny thing is, this transit, like most things, is just a matter of perspective. Our line of sight at the Sun tomorrow just happens to match up with Mercury’s path. There’s always some point somewhere in space where that happens– there’s always some spot where Mercury’s orbit is crossing directly in front of the Sun.
Tomorrow just happens to be our lucky day.