The Discovery Channel Telescope sits high on a cinder cone, overlooking the Coconino National Forest southeast of Flagstaff.

It's Arizona's newest major telescope, years in the making and now operational. The DCT, as its called, was built by Lowell Observatory, with funding help from the TV network Discovery Communications.

PHOTO: Jonathan Wilkendorf/Lowell Observatory
The Discovery Channel Telescope is located on a cinder dome in the Coconino National Forest, about 40 miles southeast of Flagstaff.

The DCT's 4.3-meter mirror will help astronomers answer some of the fundamental questions about the universe and our solar system.

The Discovery Channel filmed the evolution of the telescope over the course of seven years. Some of that footage will be seen in a documentary Scanning The Skies: The Discovery Channel Telescope, airing on The Discovery Channel Sunday, September 9 at 7:00 p.m. locally.

PHOTO: Mike Beckage/Lowell Observatory
The Discovery Channel Telescope uses a 4.3-meter mirror, making it one of the largest telescopes in the U.S.
PHOTO: Lowell Observatory Archives
A panoramic view of the interior of the Discovery Channel Telescope.