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Watch an astronaut create a space delicacy: floating balls of coffee

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The best part of waking up is coffee balls in your cup

Astronaut Jack Fischer demonstrates why coffee is so much fun to eat aboard the ISS.
Video: NASA TV and Jack Fischer

Being aboard the International Space Station gives astronaut Jack Fischer an excuse to play with his food — making mundane drinks like coffee much more fun.

“I love coffee on Earth,” he said on NASA TV in a Q&A session with elementary-school students. “But in space, I get to make balls out of it…and then suck the balls. Very cool.” In this clip, he squeezes a bag, and unappetizing brownish balls of liquid squirt from the straw. Fischer guides the hovering spheres to his face and slurps them up.

Basically, liquid coffee coalesces into gooey-looking balls in microgravity because water molecules are happiest when they’re surrounded by other water molecules. That’s their lowest energy state, which is why water molecules group together into droplets here on Earth, and into spheres when gravity isn’t pulling them downward.

The unhappy water molecules on the surface of the droplet or the sphere grip especially hard to one another, forming a sort of skin that keeps the sphere from flying apart. This phenomenon is called surface tension, and you can watch it at play when Astronaut Don Pettit pops this water balloon in space. The water that sprays free eventually undulates into spheres.

Video: NASA and Don Pettit

“As you can see, it’s pretty fun to play with your food here in space, so I do. And that pretty much makes everything my favorite dish,” Fischer said, floating away from the camera.