The Venus Transit was awesome!
Basically a Venus Transit is where Venus passes in front of the sun. It looked like a little hole in the sun. It was easier to spot later, while earlier it was nearly impossible. The link above has more images.
2004 was the last one, and the first time anyone alive at the time had ever seen a Venus transit in person, since the one before it was in 1882.
I would have used my telescope for it, but I couldn’t get solar film in time.