“Equipped with his five senses, man explores the universe around him and calls the adventure science.” — Edwin Hubble
Astronomer Edwin Hubble formally declared the existence of other galactic systems at a meeting of the American Astronomical Society on this day in 1924, a monumental discovery that forever altered our understanding of the size and nature of a universe that is itself expanding. For centuries, scientists had falsely believed that our galaxy, the Milky Way, was the center of the universe — but that was shown to be false after greater observations of space proved otherwise. Using Mount Wilson Observatory's 100-inch Hooker Telescope, Hubble had the ability to study nebulae and stars on a much larger scale than groundbreaking astronomers like Galileo Galilei. In 1990, NASA named their largest space telescope at the time in his honor — the Hubble Space Telescope has been in operation and orbiting around Earth since 1990.