Ptolemy: was an astronamor from 85-165 A.D, he formed the geocentric theory. this states that the earth was at the center of the universe and all the other planets cricled it.
Copernicus: was an astronamor lived from 1473-1543 he also belived in the geocentric theory, then he changed to the heliocentric theory which stated the distans of the planets from the sun bore on the size
NASA: sends people/astronots into space for missons to discover the wonders of space
Galileo: lived from 1564-1642 he inventid the telescope and supported the geocentric theory
aristole: lived from 322-384 BC