Travelling through space is a mind-bending proposition. Gravity gets weird, the passage of time gets weird, and you drink your own pee.

Yep, brave human beings up beyond the heavens are purifying and drinking their own urine on the ISS these days. This means that little Timmy dreaming of being the next Buzz Aldrin is probably peeing into a cup right now.

Don't do it, Timmy! Astronauts use a very expensive real-time water purifier for that!

What's the weirdest fact about space travel that you can think of?