Why is Isaasc newton discovery gravity important?

Isaac newton did not discover gravity. Practically everybody already knew that

when you let go of something in your hand, it falls to the ground, and nobody

paid any attention to the few who didn't know it. What Isaac Newton did was

explain exactly how it works, with numbers. With that simple new knowledge,

it was possible to explain how and why the moon revolves around the Earth,

how the planets and comets revolve around the sun, and how to launch spacecraft

that can carry people to the moon, land cameras on Mars, sail probes out of the

solar system, and hang satellites up in the sky that can bring you 900 TV channels

that have nothing on.

Of course, if none of that is useful or interesting to you, then Newton's discovery

wasn't important.