The Triangulum Galaxy, also informally known as the Pinwheel Galaxy, is a spiral galaxy 2.7 million light-years from Earth ...

A century ago, Edwin Hubble unveiled a groundbreaking discovery that revolutionized humanity’s understanding of the cosmos.

Pinpointing a Milepost Marker Star that Opened the Realm of Galaxies At the dawn of the 20th century, astronomers faced a ...

In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

It was entry 31 in Charles Messier's 18th century catalog of interesting fuzzy objects, and is thus also called M31 by astronomers. By the 1920's, M31 was clearly understood to be a grouping of ...

M83 was discovered in 1752 by Nicolas-Louis de Lacaille during his expedition to the Cape of Good Hope, and later cataloged by Charles Messier in 1781. This excerpt shows some of the interesting ...

The other large galaxies are the Andromeda Galaxy, and Messier 33 (the 33rd entry in Charles Messier's catalog of fuzzy things in the sky). Also in the Local Group are a couple dozen dwarf galaxies.

Messier 42 better known as the Orion Nebula, with the unaided eye from a dark sky site. This stellar relic, first spied by William Herschel in 1787, is nicknamed the Eskimo Nebula (NGC 2392) because, ...