Tour de Force: The James Webb Telescope

Abstract

The James Webb Space Telescope, known as JWST, is the next big step for observational astronomy. Figure 12.1 shows a scale model of the telescope on the campus of Johns Hopkins University. The telescope has a six and a half meter diameter mirror made of 18 smaller segments. It features a sunshield that is the size of a tennis court. The telescope has to be folded up in order to fit into the Ariane rocket that will launch it. It will take a series of complex movements in space to deploy the full telescope (see the clip on youtube entitled ‘JWST deployment’ for an animation depicting the process). JWST will operate 1 million miles from the Earth, about four times further from the Earth than the Moon is. Unlike the Hubble Space Telescope JWST will be too far away for astronauts to carry out service missions. JWST is designed to find the first stars and galaxies but will also be able to detect earth-like planets. In fact if JWST was located 25 light years from the solar system it would still be able to detect the Earth. The telescope can also peer into the molecular clouds where stars are born and see planets as they form. The telescope is designed to work at infrared wavelengths which is ideal for searching for the first galaxies.

There are other Annapurnas in the lives of men.

Maurice Herzog