TUCSON, AZ — We have an inside look at part of what makes the University of Arizona the most active university in space exploration. UA officials say the space programs launch $560 million into Arizona’s economy each year.
KGUN9 got a chance to see an important way UA helps astronomers around the world—by building a key part of the world’s most powerful telescopes.
In the Mirror Lab, a complex tucked under Arizona stadium, workers are examining glistening chunks of glass that arrived a few days ago. They’ll reject any piece with a flaw. They need perfection for the Giant Magellan Telescope being built in the high desert of Chile.
A lot has to happen before raw glass is refined into mirrors with the power to focus faint light into sharp images.
University of Arizona Professor Roger Angel led the development of a method that sets the glass chunks into a honeycomb framework, and melts the glass in an oven that spins, so centrifugal force creates a curved surface to focus the light. UA is the only place able to make mirrors as large as Magellan will use—about 27 and half feet edge to edge.
Buell Jannuzi leads UA’s Astronomy Department and its Steward Observatory. He says it takes a year and two months before the glass is ready to come out of the oven.
“It's then two or three years of polishing where we polish for 60 or 80 hours, measure the surface, figure out where we need to polish again and polish again.”
Jannuzi says the patient, precise polishing creates a focusing curve so exact, variations are many times thinner than a human hair. The glass being prepped now will become the seventh mirror the mirror lab has made for the Giant Magellan Telescope; and the latest in a long line of mirrors for powerful telescopes.
He says for many types of research, large telescopes on Earth are still stronger and more sharply focused than space telescopes like the Hubble and Webb.
“If you want to study a planet orbiting a distant star, you need to be able to separate the light from the planet and the star, the two separate images and that requires the biggest telescopes we can build.”
For Jannuzi there’s satisfaction in creating such a powerful tool to study the universe but the bigger payoff is when light flows through the telescope and the mirrors—and the scientists— focus it into knowledge.
“It's very exciting when you actually start seeing the science coming out. The science is done by the combination of a wonderful telescope and instrument that enables important or unique measurements to be made and a human with an idea that they want to test. And when that all comes together, it's very inspiring, and we learn new things.”
