The James Webb Space Telescope (JWST) is the most powerful space observatory ever built. It was launched on December 25, 2021, aboard an Ariane 5 rocket from Europe’s spaceport in French Guiana, and is a collaboration between NASA, ESA, and the Canadian Space Agency (CSA). JWST operates from the second Sun–Earth Lagrange point (L2), about 1.5 million kilometers from Earth.
Designed for infrared astronomy, JWST features a 6.5-meter primary mirror composed of 18 hexagonal, gold-coated beryllium segments. A five-layer sunshield the size of a tennis court protects the instruments from solar heat, allowing it to detect faint thermal signals from distant galaxies and exoplanets.
After completing a six-month deployment and calibration phase, JWST began full operations in mid-2022. Its four main instruments—including NIRCam and MIRI—enable observations of the first galaxies formed after the Big Bang, as well as regions where stars and planetary systems are actively forming.
Among JWST’s early achievements is the first deep-field image of galaxy cluster SMACS 0723, which revealed thousands of galaxies and offered the deepest infrared view of the universe to date.
JWST is also capable of detailed spectroscopy of exoplanet atmospheres, revealing their chemical compositions and potential signs of habitability. Its sensitivity and resolution have enabled discoveries in early galaxy evolution, star formation, and planetary system development.
Although limited by its fuel supply to an estimated 5–10 year mission duration, JWST is poised to dramatically expand our understanding of cosmic history—from the formation of the first stars to the chemical fingerprints of alien worlds.