Interior View: Weinberg College - Northwestern University

Interior View

man adjusting telescope eyepiece

The universe may be vast, but many of its secrets have been revealed by an 18.5-inch lens housed within Northwestern’s own Dearborn Observatory. Built by master craftsmen in 1862, the lens was for a time the largest in the world. Its unprecedented resolution enabled researchers to discover hundreds of double stars and nebulae and to measure the precise rate of continental drift. By the early 20th century, the Northwestern observatory had become a hub for major astronomical conferences, drawing attendees such as Edwin Hubble, whose discovery of the ever-expanding nature of the universe may well have been inspired by a talk he heard on campus in 1914. Today, the historic lens rests within a refurbished tube at the observatory, where students, faculty and visitors continue to study the timeless principles of astronomy.

The Dearborn Observatory

The 23-foot-long tube supports two smaller telescopes in addition to the original 18.5-inch lens. One is heavily filtered to enable viewing of the sun. The other features a wide-view lens that allows observers to orient themselves by locating a large "landmark," such as the moon, in the vast night sky.

Astronomers once navigated the sky with the help of this celestial sphere, which features all the constellations that would be visible from the sphere's center. Today, they position the telescope with the help of a computer, which directs the lens to the desired object.

The buttons on this panel open and close the dome and control its rotation. Critical to this mechanism is the "slow" button, which decelerates the turning dome gently. "This is really important, because that's 4,000 pounds of aluminum rotating," Smutko says. "If it stops suddenly, it could rip the wheels off."

"Unfortunately, we're not allowed on the catwalk anymore," Smutko says. "It's an 1888 catwalk; it's exactly knee height. Someone walking out there in the dark? Not a good scene."

A seemingly incongruous nautical reference in a building dedicated to the sky, this wheel once guided the telescope to its focal points in the heavens. Now retired, it adorns the door to physics and astronomy professor Mel Ulmer's office on the first floor.

The base for the telescope extends three stories downward, where's it's stabilized in the basement of the building. The rooms below the telescope are built around a progressively wider circular column that encompasses the base.