built the first telescope; a year later he discovered Jupiter has 4 moons and also discovered new stars.
He discovered the planets move in elliptical orbits with the Sun.
He discovered that Saturn's rings separated into 2 parts by a gap.
Isaac Newton discovered the theory of gravity.
He discovered what is called Halley's Comet. (only known short period comet visible to Earth)
Charles discovered a total of 13 comets before he passed and had a list of nebulous objects in the Northern Hemisphere that he also discovered.
He discovered Uranus and that it has two moons.
Albert Einstein did many things like complete the theory of relativity.
Edwin Hubble discovered that countless galaxies exist beyond just our Milky way.
Hawking showed everyone, with proof, that black holes emit radiation (this is now called Hawking radiation).