In the beginning video, you can watch astronaut Terry Virts blow a blob of water from a syringe. Water balls up in microgravity like that because the V-shaped water molecules are slightly charged. Hydrogen has a slightly positive charge, and oxygen has a slightly negative charge. This makes the hydrogen in one water molecule attracted to the oxygen in other molecules, so water tends to stick together. This effect is strongest on the surface of the water, where it’s almost as if a “skin” forms. Since this layer is interfacing with air on one side, the water molecules share fewer bonds, and that makes them stronger.