Come on, guys, guess! It'll be fun!
International Space Station astronaut Chris Hadfield just tweeted this photo of... some sort of tank or something on board the International Space Station.
Hmm. Some very important space technology, no doubt. But what could it be? Well, we got the answer pretty soon after.
Aha! It's a tank that turns urine and sweat back into drinkable water. Important indeed. In fact, we remember when the astronauts first toasted to this equipment with tall glasses of their own recycled urine. As we reported, the whole setup costs a whopping $250 million, but can you really put a price on such a futuristic toilet?