I've heard that space is full of astronaut pee. Is this correct?
-- Wondering, San Diego
Correct. But it's not exactly like they're taking a leak over the side of a boat. Before recent advances in space-toilet technology, urine was collected by creating a micro-gravity environment, stored in a holding tank, then vented into the universe. In the surrounding vacuum, the liquid would boil like crazy into a vapor, which then solidified into sparkling frozen showers of space pee. Luckily, we have never vented space poo. That's dried and stored on board, though there are stories of its escaping and floating around in the capsule on early missions. Heard enough? I think so.