What Happens To Your Tears If You Cry In Space?

Yes, astronauts can cry in space — but the tears don’t fall. With no apparent gravity to pull them down, surface tension binds the liquid into a wobbling sphere that clings to the eye and cheek, sometimes pooling into a bigger blob. The only way to get rid of it is to wipe it away.

We’ve all gotten teary-eyed from time to time, and that’s bad enough down here on Earth, but what happens up there in space, with the vast expanse of the void making you feel so small and insignificant? What if you want to shed a tear at the marvelous beauty of the universe up in the International Space Station, or what if something simply gets stuck in your eye? What happens to our tears in zero gravity? Do they just meander down our cheek and fall off like they do on Earth?

Can You Cry In Space?

Clayton C. Anderson, a NASA astronaut, had this to say about his experience up in space: “I cried in space several times… due to some very emotional circumstances. Crying is exactly the same as here on Earth, except the tears don’t fall down, as there is no gravity.  Not a big deal at all… the emotions I experienced, however, were a big deal.”

So, we know from firsthand experience that tears don’t fall. But the question is, do tears form at all in zero gravity? Well, tears are formed in small almond-shaped glands along the eyes known as lachrymal glands. Lacrima, quite fittingly, is Latin for a tear. These glands produce a thin aqueous layer in front of our eyes to keep them moist, but they’re also the source of our tears. We do not stop producing tears in space, although astronauts sometimes feel dryness in the eyes due to the clinical conditions aboard the ISS. In other words, if you’re ever up there, you can definitely shed a tear; either at the immense beauty of the earth or at your extreme loneliness.

How Does Being In Space Affect Gravity?

Up on the International Space Station, gravity certainly does exist. At ISS altitude (~400 km) it’s still about 89% of what you feel on the ground. The reason astronauts float isn’t that gravity has disappeared — it’s that they’re in continuous free fall, falling sideways in a gradual loop around the planet at about 17,500 mph. They’re always accelerating toward Earth (that’s what bends their path into an orbit), but because they fall together with the spacecraft they feel weightless — what scientists call microgravity. That being said, the ISS does keep falling ‘downwards’, so to speak, due to a phenomenon known as orbital decay. They periodically perform small ‘re-boosts’ to nudge the station back up to a higher altitude. These reboosts happen every few months (using thrusters on visiting Russian Progress or U.S. Cygnus cargo ships). It’s a bit like a swing: you can coast for a while, but eventually someone has to give you another push.

Tears In Space

Whether in a massive lake or in your glass of iced tea, liquids take the shape of the container they’re placed in down here on Earth thanks to gravity. Up in space, liquids take the shape of a sphere in their free, unregulated form. Surface tension in liquids causes molecules on the surface to pull towards each other. In space, without the effect of gravity to pull liquids downwards, they pull together to cover the smallest possible shape – a sphere.

American astronaut Andrew Feustel was on one of his scheduled spacewalks, and after five hours of floating around on the side of the ISS, he got a flake of anti-fogging solution stuck in his eye. Imagine being surrounded by nothingness, stuck in your spacesuit, without being able to rub your eye because of your helmet. This was the situation he found himself in. Thankfully, he was able to rub his eye with a small sponge stuck to the inside of his helmet, one usually used for plugging their nose during pressure readjustment procedures. If that sponge hadn’t been there, who knows how long he’d have been out there with a big ball of tears impairing his vision…

So, now we know that tears take the shape of a ball in space. Are there any illustrations of this? Thankfully, Chris Hadfield’s got us covered. As an astronaut and social media expert, his brilliant video exhibits exactly how tears form a ball around your eyes and cheek before having to be wiped away in zero gravity. Take a look!

How Do Astronauts Cry In Space?

So if the tears don’t roll down your cheeks, what does crying actually feel like up there? In Chris Hadfield’s famous demonstration aboard the ISS, he couldn’t weep on command, so he squirted drinking water into his eye to show the effect. The liquid didn’t stream away; it just sat there. As he put it, “Your eyes will definitely cry in space, but the big difference is, tears don’t fall.” Instead, every fresh tear you produce gets added to the same growing blob. Keep crying and that blob keeps swelling, a wobbling sphere of saltwater stuck to your eye and cheek, held there by surface tension alone.

There’s a catch, though: a tear blob can’t grow forever. Once it gets heavy enough with liquid, it can creep across the bridge of your nose and slide straight into your other eye. So crying in space doesn’t leave you with neat streaks; it leaves you with a quivering puddle clinging to your face. The only way to clear it is to physically mop it up, which is exactly what Hadfield did, dabbing the water away with a towel just as you would at home so the droplets wouldn’t break free and drift off into the cabin.

The most dramatic version of this happened to Hadfield outside the spacecraft. On 22 April 2001, during the STS-100 mission, he became the first Canadian to walk in space, and a flake of the anti-fog solution used to keep visors clear got into his left eye. It stung badly and his eye flooded with tears. With no gravity to drain them, the liquid pooled, bridged his nose and crept into his other eye, leaving him briefly blind on both sides while clipped to the outside of the station. He stayed calm, vented some suit oxygen to help the contaminant evaporate, and his sight gradually returned. NASA has since worked to replace that troublesome wipe-on solution, because the watering and irritation it caused is a known hazard during spacewalks. It’s a vivid reminder that on Earth gravity quietly does the housekeeping for our tears, and in orbit you have to do it yourself.