Its field of view is also about 15 times that of Hubble. In the JWST this has been solved with a passive system of solar shields and a cryogenic refrigerator, thus avoiding the use of refrigerants such as helium or nitrogen used in other previous instruments, which eventually evaporate.īut apart from its increased infrared coverage, the JWST is a much more sensitive eye than its predecessor: its 6.5-metre mirror, compared to Hubble’s 2.4 metres, gives it a surface area of 25 square metres, more than six times larger than that of its predecessor. Reaching the mid-infrared presents an additional technical complication, the need to keep the telescope extremely cold-below 50 kelvin or -223☌-so that the telescope’s own thermal radiation does not blind it, something akin to what happened to old photographic film when it was exposed to too much light. The JWST is a much more sensitive eye than its predecessor: its 6.5-metre mirror gives it a field of view about 15 times that of Hubble.

This is also why infrared telescopes must circumvent the blockage of this radiation by the Earth’s atmosphere, and for this reason space is the ideal location. As more distant-and therefore older-astronomical objects have a higher redshift in the light they emit, a telescope with greater infrared coverage is needed to observe them. The JWST has often been presented as the replacement for Hubble, but NASA prefers to speak of the successor it sounds the same, but there is a nuance: the new eye of humans in space will not limit itself to continuing the work of its predecessor, but will expand its domains especially in the infrared, a band of the light spectrum in which Hubble only reaches the near band, just adjacent to visible light.

Since its long-awaited launch on Christmas Day 2021, the James Webb Space Telescope (JWST), developed by NASA-in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA)-has not only begun to live up to the expectations of researchers but is also one of those scientific endeavours that manages to engage the media and the public with captivating images of a previously uncharted universe. It has been said that it is more than a just a telescope it is more like a time machine that allows us to look back into the remote past of the universe that has been inaccessible until now.

First images webb space telescope