Harlow Shapley was an American astronomer born on November 2, 1885, in Nashville, Missouri. He is best known for his work in determining the size and structure of the Milky Way galaxy. Shapley used globular clusters to estimate the galaxy's dimensions and concluded that the Sun is located far from the center, which was a significant shift in understanding our place in the universe. In addition to his research, Shapley played a crucial role in the development of modern astronomy. He served as the director of the Harvard College Observatory and was influential in promoting the importance of observational astronomy. His contributions helped lay the groundwork for future discoveries in the field.