This story is free to read because readers choose to support LAist. If you find value in independent local reporting, make a donation to power our newsroom today.
Making a Giant Mirror to Scour the Skies
Listen
0:00
Listen
An artists' conception of the Giant Magellan Telescope, scheduled to see first light in 2016. The telescope will have a central mirror surrounded by six 27-foot-diameter mirrors.
(
/
)
Over the past 20 years, a new generation of big telescopes has allowed astronomers to discover distant planets and galaxies. But those telescopes are runts compared to what's coming. Mirrors for what will be the world's largest telescope are now being made at the University of Arizona.
The Steward Observatory Mirror Lab recently began casting the first of seven mirrors -- each 27 feet in diameter -- that will become part of the Giant Magellan Telescope, creating an enormous reflective surface of glass.
The facility uses a unique process to cast single-piece mirrors so large. Twenty tons of glass are spun inside a two-story rotating furnace to create a naturally concave mirror. The bowl shape is highly effective at gathering and focusing light. As the glass melts, it flows around ceramic forms inside the furnace, creating a mirror a few inches thick on top of a glass honeycomb. That makes it just one-fifth the weight of a solid mirror.
Cooling the furnace will take almost three months. After that, the mirror will be moved to another room for polishing, a process that takes about a year. The finished product will be accurate to within one-billionth of a meter.
Eventually, the giant mirror will end up on a mountaintop in Chile, where it will join six others surrounding a seventh central mirror to become part of the Giant Magellan Telescope.
The Giant Magellan will have 10 times the resolution of the Hubble. Astronomers hope those powerful optics will help them look directly at some of the dozens of planets spotted orbiting other stars.
Sponsored message
Copyright 2022 NPR. To see more, visit https://www.npr.org. 9(MDA1OTI3MjQ5MDEyODUwMTE2MzM1YzNmZA004))
You come to LAist because you want independent reporting and trustworthy local information. Our newsroom doesn’t answer to shareholders looking to turn a profit. Instead, we answer to you and our connected community. We are free to tell the full truth, to hold power to account without fear or favor, and to follow facts wherever they lead. Our only loyalty is to our audiences and our mission: to inform, engage, and strengthen our community.
Right now, LAist has lost $1.7M in annual funding due to Congress clawing back money already approved. The support we receive from readers like you will determine how fully our newsroom can continue informing, serving, and strengthening Southern California.
If this story helped you today, please become a monthly member today to help sustain this mission. It just takes 1 minute to donate below.
Your tax-deductible donation keeps LAist independent and accessible to everyone.
Right now, LAist has lost $1.7M in annual funding due to Congress clawing back money already approved. The support we receive from readers like you will determine how fully our newsroom can continue informing, serving, and strengthening Southern California.
If this story helped you today, please become a monthly member today to help sustain this mission. It just takes 1 minute to donate below.
Your tax-deductible donation keeps LAist independent and accessible to everyone.
Senior Vice President News, Editor in Chief
