A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the ...
Pinpointing a Milepost Marker Star that Opened the Realm of Galaxies At the dawn of the 20th century, astronomers faced a ...
NASA’s recent Image of the Day was the outer regions of the Tarantula Nebula, which is billed as one of the biggest and ...
Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they were independent galaxies, extremely large and distant. At the time ...
In the century since Hubble’s pioneering work, astronomers like me have learned that the universe is vast and contains trillions of galaxies. Nature of the nebulae In 1610, astronomer Galileo ...