Cosmic Time Machine: The Jaw-Dropping Science Unleashed by the James Webb Space Telescope
JWST launched on December 25, 2021, aboard an ESA Ariane 5 rocket to the Sun-Earth L2 point, reaching about 1.5 million kilometers from Earth in January 2022. Its 6.5-meter segmented gold-coated beryllium primary mirror consists of 18 hexagonal segments, each about 1.32 meters across and roughly 20 kilograms, designed to fold for launch. JWST uses a five-layer Kapton sunshield measuring roughly 21 by 14 meters to keep the optics around 40 kelvin, while the MIRI instrument operates at about 7 kelvin with a dedicated cryocooler. JWST carries four main instruments: NIRCam (0.6-5 μm; 4-megapixel arrays and wavefront sensing), NIRSpec (0.6-5