Scientists began casting one of the largest telescope mirrors ever created on Earth for the Giant Magellan Telescope being built in Chile on Friday.
Why it matters: The huge telescope is designed to once look into the atmospheres of potentially habitable planets around distant stars, learn more about early galaxies, and study other interesting objects.
What is going on: The mirror is made in Arizona using the world’s only revolving furnace designed for these types of castings.
- On Saturday, the furnace will hit “high heat,” spinning at five revolutions per minute, and heating the glass to 2,129 degrees Fahrenheit for about five hours to liquefy it.
- After that peak in heating, the glass will cool gradually over about a month as the furnace slows down and eventually reaches room temperature about 2.5 months after high heat.
- “Once cooled, the mirror will be polished for two years before reaching an optical surface precision less than one-thousandth the width of a human hair or five times smaller than a single coronavirus particle,” the GMT organization wrote in a press release.
What’s next: The first two mirrors of the GMT are ready and saved, and three others are still in progress. The seventh and finally Mirror is scheduled to be cast in 2023.
- The team behind the telescope also plans to make an eighth mirror as a spare.
- The telescope is expected to see light for the first time in 2029.