World News Headlines January 6, 2022 Under One Ceiling 0 Why Webb’s unassuming secondary mirror makes it a telescope 0 0000 0 0 more Why Webb’s unassuming secondary mirror makes it a telescope January 6, 2022 Under One Ceiling now playing Transferring money from UAE abroad: what are my cheapest options January 6, 2022 Under One Ceiling WIN With Nespresso This Mother’s Day January 6, 2022 Under One Ceiling NBA Playoffs 2022: A Casual Fan's Guide to the Postseason January 6, 2022 Under One Ceiling Best New Climbing Gear of 2022 January 6, 2022 Under One Ceiling A Local Weekend Travel Guide to Austin, Texas January 6, 2022 Under One Ceiling First Drive: 2022 Range Rover Ups the Luxury SUV Experience January 6, 2022 Under One Ceiling Most Stylish Rain Jackets, Parkas, and Trench Coats for Men January 6, 2022 Under One Ceiling EU eyes Russian oil import ban as Moscow strikes western Ukraine January 6, 2022 Under One Ceiling World-class Clark Int’l Airport opens new 110,000 square-meter passenger terminal January 6, 2022 Under One Ceiling PCG: Bodies of 5 children who drowned in Taal Lake found January 6, 2022 Under One Ceiling Why Webb’s unassuming secondary mirror makes it a telescope The James Webb telescope has a two-story concave mirror that looks like a golden honeycomb dish. On Wednesday, that’s not what NASA opened. What it did deploy was a much smaller mirror — a round convex piece only 2.4 feet in diameter, about that of a car tire. But the Webb team cautions against underestimating its significance. As program manager Bill Oakes said during the live broadcast of the deployment: “We’re about 600,000 miles from Earth, and we actually have a telescope.” So what is it about the secondary mirror that makes this thing a telescope? “This will allow the light to actually go into the telescope,” said Michelle Thaller, a NASA spokeswoman. SEE ALSO: Looking for new James Webb telescope pictures? You’ll have to wait. Without the small mirror there to gather and concentrate the light reflected off the primary honeycomb mirror, Webb would not be able to perform the science it’s expected to accomplish. The second mirror is positioned way in front of the honeycomb and will collect light from the 18 hexagonal honeycomb segments, focusing them into a beam. The light is concentrated by bouncing off the secondary’s curved surface. Then, the beam is directed into a third mirror and other so-called “fine-steering” mirrors before being channeled into Webb’s scientific instruments. If the secondary mirror — the focusing mechanism — isn’t in the right position, no light goes into the telescope. “The beam is shaped and reflected back to the secondary (mirror), which is convex,” said Julie Van Campen, Webb’s deputy commissioning manager, “and then it pushes it down through the center of the telescope.” The deployment Wednesday involved a large tripod with 25-foot-long legs outstretching from the primary mirror, holding the smaller mirror in front of it. (The above video shows the maneuver being demonstrated in a ground test.) Webb is a telescope now. If all goes well, it’ll be a much bigger telescope by the end of the week. Related Related posts: Coronavirus: England to scrap quarantine for arrivals from ‘low risk’ countries Internet shut down and Indian troops deployed after death of Kashmir separatist leader New Android accessibility features let users control phones with facial movements tags: RSS Feed World News 0000 0 0 previous Novak Djokovic: Australia cancels top tennis player's visa next A closer look at Fisker Ocean EV's solar-paneled roof in high-speed video
