You can cry in the zero gravity of space, but the tears won't stream down your face like they do on Earth. That's what astronaut Andrew Feustel discovered during a spacewalk in 2011. He wasn't actually weeping out of sadness -- his eye was watering because a small irritant had lodged there during a seven-hour repair mission outside the International Space Station. The tears "don't fall off of your eye, they kind of stay there," he said later, describing the "liquid ball" that clung to his eyeball.
Floating tears and other effects of crying in space: