James Webb Space Telescope

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Life-sized model of JWST shown at the 2007 AAS meeting in Seattle, Washington. It stands two stories high and weighs several tons. Credit: Rob Gutro, NASA/GSFC.

James Webb Space Telescope (JWST) is a telescope that will be put into space. It is planned to be launched in 2021. It is a replacement for the Hubble Space Telescope which was launched in 1990.[1]

The telescope is named after James E. Webb, who was a director at NASA and created the Apollo program that put astronauts on the moon.

It will have a main mirror that is 6.5 metres (21 feet) wide. This is 6 times larger in area than Hubble. It is so large it is made in 18 pieces that fold together during the launch, so that it can fit into a rocket. It is mainly an infrared telescope but also works in the red part of the visible light (the pictures will be coded with false color so we can see them). It is plated with gold because gold reflects infrared very well. It will be able to see things that the Hubble Space Telescope cannot. Infrared vision can be used to see heat radiation (like some kinds of night vision goggles), so the telescope itself must be kept as cool as possible. It is protected by a large sunshield the size of a tennis court to keep it cool and dark.

Orbit[change | change source]

JWST orbit (not to scale)

The JWST will be in orbit far from Earth, to avoid heat radiating from the Earth and moon. This special orbit is beyond the moon, at the second Lagrange point (L2) of the Sun-Earth system, a place of stable gravity. This orbit is 1,500,000 kilometres (930,000 miles) from Earth, about four times farther away from us than the moon.[2] This keeps it in the Earth's shadow most of the time; it does not actually go around the Earth, but goes around the sun at the same speed as the Earth.[3]

References[change | change source]

  1. "James Webb Space Telescope". NASA. Retrieved 14 May 2013.
  2. "Webb Telescope mirrors: Stepping stones to the cosmos". NASA. Retrieved 6 January 2017.
  3. "Interview on JWST". NPR. Retrieved 14 May 2013.