This week marks the centennial of Mt. Wilson's 100-inch telescope. When it gathered its first light, it overtook its 60-inch neighbor and became the largest telescope in the world — a position ...

“In 1908 it was the largest telescope in the world,” says telescope operator Tom Mason. He’s one of a devoted cadre of amateur astronomers and retired engineers who keep things going atop Mt. Wilson.

“In 1908 it was the largest telescope in the world,” says telescope operator Tom Mason. He’s one of a devoted cadre of amateur astronomers and retired engineers who keep things going atop Mt. Wilson.

The 100-inch telescope mirror is transported to Mt. Wilson Observatory in July 1917. (Courtesy of the Observatories of the Carnegie Institution for Science Collection at the Huntington Library) ...

Perched atop California’s Mount Wilson, the 100-inch reflecting telescope took “first light” on the night of Nov. 1, 1917. The name “100-inch” isn’t the size of the entire telescope.

Hale quickly got to work building an even bigger telescope on Mount Wilson than he’d had back in Wisconsin, and in December 1908, a new 60-inch telescope was used for the first time, dwarfing ...

In the 1920s, Edwin Hubble was working with the 100-inch Hooker telescope on Mount Wilson, just outside Los Angeles. At the time, it was the largest telescope in the world. On a chilly evening, I ...

Dating back to 1904, Mount Wilson Observatory was founded by Dr. George Ellery Hale in the mountains of Pasadena where some of the world's oldest telescopes are housed. When Hale established the ...

Tom Meneghini, executive director of the Mount Wilson Institute, is photographed Sept. 23 next to the 100-inch Hooker telescope located at the Mount Wilson Observatory in Los Angeles.

In the 1920s, Edwin Hubble was working with the 100-inch Hooker telescope on Mount Wilson, just outside Los Angeles. At the time, it was the largest telescope in the world. On a chilly evening, I ...