Happy birthday to Mount Wilson’s historic telescope

This celebration requires 60 inches of mirror and 100 candles.
By | Published: December 12, 2008 | Last updated on May 18, 2023
60-inch telescope at Mount Wilson Observatory
On December 13, 1908, astronomers first gazed at the heavens with the 60-inch telescope at Mount Wilson Observatory in California. It was the most technologically advanced viewing instrument of its age. Credit: MWO
Mount Wilson Observatory
Hale brothers look through Mount Wilson 60-inch telescope
Brothers Sam (left) and Brack Hale look through the historic 60-inch telescope founded 100 years earlier by their grandfather, pioneer astronomer George Ellery Hale.
Courtesy Craig T. Mathew/Mathew Imaging
December 12, 2008
Mount Wilson Observatory (MWO) marked an important anniversary December 13. It has been 100 years since pioneer astronomer George Ellery Hale first gazed at the heavens through the observatory’s historic 60-inch reflecting telescope.

The 60-inch was Earth’s largest telescope at the time it was built. Creating its 1,900-pound mirror was a technological triumph. It established a new standard for large, precision-controlled reflecting telescopes.

The 60-inch established MWO as a leader in astronomical discoveries in the early 20th century. For example, Harlow Shapley used it to discover that our Sun was not the center of the universe, and that our galaxy is far larger than anyone imagined.

MWO’s current director, Harold McAlister, says the anniversary is an occasion to look backward as well as forward. “The centennial naturally brings the telescope’s technological and scientific greatness to the front of my mind,” he says. “This event makes me even more determined that a second century be assured for Mount Wilson, which truly is a world-class science heritage site.”

Related blog: Senior Editor Daniel Pendick spoke with McAlister about the 60-inch telescope’s place in astronomical history and its current scientific activities. Read “Happy birthday to a grand old telescope.”

MWO’s 100-inch Hooker Telescope is still used for research. And the 60-inch remains the largest telescope in the world made exclusively available for public viewing. Read about the observatory’s public programs and efforts to preserve the site and its instruments at the MWO web site.