James Webb Space Telescope (JWST)

The James Webb Space Telescope (JWST) is a next generation telescope, to replace the Hubble Space Telescope when it retires in 2021. JWST is a NASA project, in collaboration with the European Space Agency and the Canadian Space Agency.

Artist's impression of the James Webb Space Telescope
Credit: NASA/JWST

Some facts about the telescope:

  • Observatory location: In orbit around the Sun
  • Distance: 1,500,00 km from Earth
  • Mass: 6,500 kg
  • Mirror diameter: 6.5 metres
  • Launch date: October 2018

The mirror on the JWST is made of 18 hexagonal segments, arranged together to form one large mirror. A traditional 6.5 metre mirror would be too large for the launch vehicle, and so the small segments will unfold after the telescope is launched. Each mirror segment is 1.3 metres in diameter.
A larger telescope mirror gives a larger area to collect light. This means that the telescope can see fainter objects, and smaller details. JWST will look at visible and infra-red light. Its science goals are to investigate: