I created the heliocentric theory: Which helped to understand that the Earth and the other planets revolved around the Sun, as a curious fact was postulated a year after my death in 1543.
I did several works in trigonometry: Which improved the accuracy of astronomical measurements.
I made several researches on the motion of the planets: which improved the understanding of their orbit around the Sun.
I developed astronomical instruments: Which facilitate to this day, and observations of the sky.