How can a rocket move through space when there is nothing to push again?

A rocket moves through space by utilizing Newton's third law of motion: for every action, there is an equal and opposite reaction. It expels gas out of its engines at high speed, creating thrust that propels the rocket in the opposite direction, even in the vacuum of space. This means that the rocket doesn't need anything to push against; the expelled gases provide the necessary force to move. Thus, the principle of momentum allows the rocket to accelerate and maneuver in the absence of air or other materials.