How do liquids move in space?

Earth's gravity significantly influences the movement of liquids. For this reason, liquids behave differently on Earth and in a weightless environment, for example, in the International Space Station. Another effect that affects the movement of liquids is intermolecular forces.

The effect of gravity on Earth overcomes the effect of intermolecular forces. For this reason, liquids act on Earth's gravitational force. However, intermolecular forces begin to become apparent under unweighted ambient conditions in space.

Fluids form a spherical shape under the influence of surface tension under unweighted ambient conditions. Due to the attraction force of liquid molecules, each molecule is attracted equally by other molecules around it. However, the attraction force acting on the molecules on the surface of the liquid is not balanced. For this reason, liquids in the weightless environment are found spherically, with the smallest surface area. Whether a liquid in a container in a weightless environment will be dispersed in the form of spherical droplets or spread completely on the surface of the container depends on the magnitude of the attraction (adhesion) between the attraction force (cohesion) between the molecules forming the liquid and the different molecules - for example, the liquid and the surface of the container.