Existence of Other Galaxies Is Announced
The announcement of the existence of other galaxies beyond the Milky Way was made by American astronomer Edwin Hubble on December 30, 1924. Prior to this revelation, the cosmos was thought to be primarily composed of the Milky Way galaxy, which contains around 200 billion stars and spans approximately 100,000 light years in diameter. Hubble's work at the Mount Wilson Observatory, utilizing the powerful 100-inch Hooker Telescope, revealed that what were previously considered nebulae were actually separate galaxies within the universe. His findings indicated not only the presence of around 125 billion galaxies, including the nearby Great Andromeda Spiral Galaxy, but also suggested that the universe itself is expanding. Hubble's groundbreaking discoveries transformed our understanding of the universe and contributed to his rise as a notable figure in both the scientific community and popular culture. His research laid the foundation for modern cosmology, inviting further exploration into the vastness of space and the nature of galaxies. This pivotal moment marked a significant advancement in astronomy, illuminating the complexity and scale of the universe we inhabit.
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Existence of Other Galaxies Is Announced
Existence of Other Galaxies Is Announced
On December 30, 1924, the American astronomer Edwin Hubble announced the existence of other galaxies in addition to the Milky Way, of which the Sun and its solar system are a part.
Virtually all stars are organized into large bodies called galaxies. The Milky Way contains approximately 200 billion stars in addition to the Sun. About 100,000 light years in diameter, like most galaxies the Milky Way consists of large spiral arms of stars which slowly rotate around a massive globular center that may well contain a large black hole at its core. There are an estimated 125 billion galaxies in the universe, some of which are over a dozen times as large as the Milky Way. The nearest galaxy is the Great Andromeda Spiral Galaxy, about a million light years from Earth. Galaxies have been observed by astronomers for centuries, but it was Hubble who first determined that these mysterious bodies known as nebulae were part of the universe's system of galaxies which includes the Milky Way itself. He made his discovery at the Carnegie Institution's Mount Wilson Observatory in California, where he was a resident astronomer. Using the Mount Wilson 100-inch Hooker Telescope, the most powerful telescope in the world at the time, Hubble determined not only that numerous galaxies exist in addition to our own, but also that the universe is expanding. His discoveries made Hubble famous overnight and something of a celebrity among Hollywood's more earthly stars.