Contributions to N + S of Milky Way

Galileo: Galileo observed the Milky Way, which was previously believed too be nebulous, He found it to be a magnitude of stars packed extremely dense instead of what people thought to be simply nebulas.

William Herschel: Helped establish the shape of the milky way with the large telescopes. He helped establish that we in fact live in the milky way and that the fuzzy patches observed were nebulae. By measuring the stars, he helped establish that we live in what he called a disk of stars. 

Harlow Shapley: Helped expand our knowledge on the shape of the milky way. He began by studying globular clusters around the time when the shape of the galaxy was unknown. But after his research was published, the shape and the position of our solar system in the galaxy was known. 

Edwin Hubble: He helped understand that the cloudy patches observed were not nebulae but other nearby galaxies. This helped understand the size of the universe. He also helped by stating that the universe was in fact expanding.

Immanuel Kant:  Believed the milky way was disk shape but never achieved much work on it.

Henrietta Leavitt: Discovered the period luminosity relation.

The Great Debate: Between Curtis and Shapley, Shapley held the position that the spiral nebula we call galaxies were inside the milky way. Curtis argued they were outside.