You may have heard the phrase, "What goes up, must come down." But why is this? It is because everything (you, me, rockets, raindrops) is being pulled toward the Earth by gravity. The strength of this pull is stronger for bigger objects but gets weaker for objects that are far apart. Rockets are only able to escape the pull of the Earth's gravity by burning huge amounts of fuel to create an upwards "push" force that is stronger than gravity's "pull."
What is amazing is that gravity is not special to Earth; all objects in the Universe feel the same type of gravity force, which holds stars, solar systems, and galaxies together. Even 100 years ago, astronomers knew how to predict where objects in the solar system should appear in the night sky. But they did not know what gravity really was. This is when Albert Einstein had a very big idea: what we call gravity is not really a "pull force" like being attached to a rope. In Einstein's theory, space is more like a stretchy blanket than a hard table; every object makes a dip in this blanket, but bigger objects make bigger dips.

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Go to source: https://kids.frontiersin.org/article/10.3389/frym.2019.00080