Scientists on Friday began casting the largest ever telescope mirrors ever made on Earth for the Chilean-built Giant Magellan Telescope.
Why it’s important: The giant telescope, built to peer one day into the atmosphere of potentially habitable planets around distant stars, can learn more about early galaxies and study other things of interest.
What’s happening: The mirror is being designed in Arizona using the world’s only spinning furnace built for this type of casting.
- On Saturday, the furnace will sound a spinning “high fire” at five revolutions per minute and heat the glass to 2,129 degrees Fahrenheit for about five hours to liquefy it.
- After those peaks of heating, the glass will slowly cool for about a month when the furnace expands more slowly, eventually reaching room temperature. About 2.5 months after high fire.
- “Once cooled, the darshan will be polished for two years, before reaching the precision of the optical surface, which is less than a thousandth of the width of human hair or five times smaller than a single coronavirus particle,” the GMT said in a press release.
What’s next: The first two mirrors of GMT are ready and in storage, with the other three still in process. Seventh – And last – Mirror cast in 2023.
- The team behind the telescope is also planning to make an eighth mirror as a spare.
- The telescope is expected to see the first light in 2029.
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