Earlier this year, high above Earth, astronaut Scott Kelley demonstrated in this video how water behaves when it’s freed from the constraints of gravity. Turns out, space water likes to ball.
Water is water, though, and you can still mix it with other fluids—they just join in the spherical party. Kelley starts his cool demonstration aboard the International Space Station with a drop of red food coloring. On Earth, food coloring would drop down into water, of course. Here, it doesn’t go down, it goes in, as if the water’s ingesting it. Kelley’s crystal-clear orb instantly turns red. It may be that Kelley’s making a point about how easily water’s affected by all the crap we put into it down here on Earth. He mixes in a few drops of blue coloring before the camera cuts away.
When we return, the water ball’s green, and Kelley has something a little weird to try. He inserts—again, from the side—what looks suspiciously like an Alka-Seltzer tablet. It’s definitely an effervescent of some sort. In a few moments, the little green blob is shooting off the tiny, burp-inducing bubbles the tablet produces as it dissolves.
Not all of the tummy-settling gas escapes, though, and the orb winds up with big pockets of the stuff lurking beneath its green surface as it slowly rotates like a tiny green earth.