Going to space, the final frontier, is incredible, and for most people, unknowable. But because we’re humans, whenever an astronaut does an AMA or gets interviewed, or even just has Twitter, it’s always the weird details people want to know about.
Do people want to know if astronauts really do experience Orbital Awareness (the profound feeling of awareness and empathy reported by those who have left Earth)? No, they want to know how you pee in zero gravity, has anyone ever had sex in space, and what happens if you vomit?
Former Commander, astronaut, and fighter pilot Chris Hadfield is also quite the helpful science communicator, often offering up interesting tidbits about life in space, and is usually game when quizzed by enquiring minds.
Which is exactly what happened here when a curious Twitter-user asked him if the “real fact” they’d come across was in fact true (props for checking before sharing!).
“Is this true @Cmdr_Hadfield?” they tweeted, sharing a photo of a bottle top with the words “Real Fact #1450. Astronauts can’t burp in space.”
“If so, why not?”
Hadfield indeed answered, with some rather stomach-churning details.
“You can't burp in space because the air, food and liquids in your stomach are all floating together like chunky bubbles,” he wrote.
“If you burp, you throw up into your mouth. So guess where the trapped air goes?”
So, yes, it’s true that you can’t burp in space, at least not in the same way that you can on Earth, and it’s all thanks to gravity – or the lack of.
On Earth, gravity helps keep the food and juices in your stomach stay where they are. If gas gets trapped there too, it just rises as it’s lighter than solids and liquids, and comes out of your mouth as a burp.
In space, there’s no gravity to keep anything in its place, so if you burp, the air will indeed come out of your mouth, but so will everything else in your stomach. The National Space Centre christened this “bomit” back in 2012.
As a resident of the ISS, you definitely don't want to be dealing with other people's bodily fluids floating about around you, although sometimes that can't be helped.
Earlier this year, retired astronaut Scott Kelly described a rather unpleasant incident experienced during his record-breaking time on the ISS that involved a "gallon-sized ball of urine mixed with acid", which is used to stop the toilets from clogging up.
Surgery in space doesn't sound like much fun either.
Most famously of course was the floating number two that haunted the Apollo 10 mission in 1969, with Commander Tom Stafford's words forever immortalized in NASA transcripts.
“Give me a napkin quick,” he is heard saying to his colleagues. “There’s a turd floating through the air.”