The discoveries of astronomers like copernicus and galileo

Established that the universe was sun center or heliocentric

Explanation:

They (Copernicus and Galileo) disproved with separate theories that the earlier claim by Ptolemy that the earth was stationary and that it is the center of the universe meaning that the planets, the stars and the sun revolves round the earth. Copernicus used geocentric theory to disprove the claim and Galileo use a self built telescope to observe the plenary motion of the moons of Jupiter round Jupiter and with other similar observations he like Copernicus established that the sun, not the earth is at the center of the universe.