The largest space telescope ever launched
James Webb Space Telescope
The James Webb Space Telescope, a partnership of NASA, ESA and the Canadian Space Agency, launched on 25 December 2021. It observes the universe in infrared light from a halo orbit around the Sun–Earth L2 point, about 1.5 million km from Earth.
Its sensitivity lets it study the first galaxies, the birth of stars and planets, and the atmospheres of worlds orbiting other stars.
Key facts
- Agency
- NASA / ESA / CSA
- Launched
- 2021-12-25
- Launch vehicle
- Ariane 5
- Power
- Solar array
- Mission type
- Space observatory
- Primary mirror
- 6.5 m, 18 segments
- Status
- Operating at the Sun–Earth L2 point
Where it is now
Loading live position from NASA/JPL Horizons…
Remains near Sun–Earth L2.
Mission objectives
Webb is designed to observe light from the earliest galaxies, peer through dust to watch stars and planetary systems form, and measure the composition of exoplanet atmospheres.
The observatory
Its primary mirror is made of 18 hexagonal gold-coated beryllium segments that unfolded in space. A five-layer sunshield about the size of a tennis court keeps the telescope cold enough to detect faint infrared light.
Instruments
NIRCam, NIRSpec, MIRI and NIRISS, together with a fine guidance sensor, cover near- and mid-infrared wavelengths.
Discoveries and highlights
Since science operations began in July 2022, Webb has found surprisingly bright, distant galaxies from the universe's first few hundred million years and detected carbon dioxide and other molecules in exoplanet atmospheres.
Route and timeline
- 2021-12-25Launch on Ariane 5, Kourou
- 2022-01-24Arrived at L2
- 2022-07-12First science images released
Surprising facts about James Webb Space Telescope
- Webb's orbit around L2 keeps the Sun, Earth and Moon behind its sunshield.
- Its mirror segments can be adjusted by tiny fractions of the width of a human hair.
- A precise launch left it enough fuel for a mission expected to last well beyond its original ten-year goal.