Charles Darwin (1809–1882) was a British scientist whose work on evolution—the way living things change over generations—revolutionized.

Edwin Hubble

We used to think that our own galaxy was the entire universe. Edwin Hubble expanded that understanding to unimaginable distances. Before Hubble, we didn't know about distant galaxies. Telescopes of the time saw only fuzzy areas of what were deemed gas clouds and dust, referred to as nebulae.

Edwin Hubble discovered that other galaxies exist outside the Milky Way. His work led to our current understanding of the expansion of the universe.

Edwin Hubble, American astronomer who played a crucial role in establishing the field of extragalactic astronomy and is generally regarded as the leading observational cosmologist of the 20th century. Learn more about Hubble and his work, including his notable research and discoveries.

#Today In History In 1924, American astronomer Edwin Hubble pointed out that the Andromeda galaxy does not belong to the Milky Way, and there are many galaxies in the universe. He is recognized as the founder of galaxy astronomy and the pioneer of observational cosmology, and is honored as the father of galaxy astronomy by the astronomy community.

Axions? Phantom energy? Astrophysicists scramble to patch a hole in the universe, rewriting cosmic history in the process.

A small discrepancy in the value of a long-sought number has fostered a debate about just how well we know the cosmos.

Edwin Hubble