OK, so I stole the title from my own main page. I can't very well sue myself.
But Mercury is pretty cool right now. I've been watching it the past few nights, and it's sinking like a rock (har har) in the sunset. It was up pretty high just a few nights ago, but now it's noticeably lower. It screams around the Sun in only 88 days, so every day at the same time you can see how far it's moved.
This is a picture I took of Mercury and the Moon just the other night. By tonight the Moon'll be way out of frame to the top, and Mercury will be lower. It's pretty amazing. Mercury is pretty dinky (5000 kilometers across, while the Earth is more like 13,000) and pretty far away (47 million km as I write this), so it's cool we can see it at all.
They say (whoever "they" are) that the great astronomer Copernicus never saw Mercury. It was too foggy in Poland in the mornings and evenings, and Mercury never gets far from the Sun. At sunrise and sunset it was also too cruddy outside for him to see it. Given that, I would think he was kind of a loser, except for that whole coming up with heliocentrism thing. I have personally never revolutionized astronomy, so I have to give him substantial credit for that.