Sophie and I went out last week to see the International Space Station and Space Shuttle as they flew over just after sunset. Very impressive brightness, and we noticed a bright cloud of vapor surrounding the shuttle, like something venting into space.
Well, turns out that was astronaut pee. Popular Science has a story and photo gallery of it, including a photo from an amateur astronomer in Madison, which pretty much caught our point of view.
When I was in high school, in the pre-internet days, my informative speech in forensics one year required me to send away for information from NASA about toilets in space. Never did I dream that they would give us such a display from the heavens!