Just how do astronauts keep their whites pearly while up in outer space?
Canadian astronaut Chris Hadfield, who is currently helming the International Space Station, recently posted a video explaining how the dental cleaning process works for those living in zero gravity.
Hadfield says astronauts use a standard (non-electric) toothbrush and regular old toothpaste to get the job done.
"We don't have running water, "he explains. "You can't have a tap; you can't have a sink because water would flow everywhere."
He then goes on to demonstrate the process, joking between brushes that you should clean "as long it takes to sing happy birthday." What happens to the toothpaste and spit when he's finished brushing?
Find out in the video below.
You can learn more about hygiene in space on the Canadian Space Agency's website.