James Webb Space Telescope has sent back its clearest image yet

A crucial phase of mirror alignment has been completed for the James Webb Space Telescope, and the process resulted in the highest resolution infrared image ever taken from space

Space

16 March 2022

By Leah Crane

While the purpose of this image was to focus on the bright star at the center for alignment evaluation, Webb's optics and NIRCam are so sensitive that the galaxies and stars seen in the background show up. At this stage of Webb?s mirror alignment, known as ?fine phasing,? each of the primary mirror segments have been adjusted to produce one unified image of the same star using only the NIRCam instrument. This image of the star, which is called 2MASS J17554042+6551277, uses a red filter to optimize visual contrast. — The James Webb Space Telescope focused on this bright star to align its mirrors

NASA/STScI

The James Webb Space Telescope (JWST) has reached a critical phase in the alignment of its mirrors. Images from this process have shown that everything is working even better than expected, and the telescope’s operators say that its performance will be able to meet or even exceed the goals that were originally set for it.

JWST peers into the cosmos with the help of 18 gold-plated hexagonal mirrors. For it to work properly, all of these mirrors have to be aligned with extraordinary precision – within nanometres – so that they act as one. When the observatory sent back its first images in February, the mirrors were not yet aligned and the images were blurry. Now, while the alignment process is not entirely complete, the image is crystal clear.

“This is as sharp an image as you can get from a telescope of this size,” said JWST scientist Marshall Perrin at the Space Telescope Science Institute in Maryland during a 16 March press conference. It is the highest resolution infrared image ever taken from space.

The picture itself shows a bright star called 2MASS J17554042+6551277. If the alignment had not been precise enough, there would be multiple copies of the star in the image, but it shows that the mirrors are now all working together to create a single image of a star flanked by distant galaxies.

“The telescope performance so far is everything that we dared hope,” said JWST scientist Jane Rigby at NASA’s Goddard Space Flight Center in Maryland during the press conference. There are a few more alignment steps before the observatory can take its first science images, which are expected in June or July.

This image of a single star is only the beginning. Once JWST begins taking science images, researchers expect it to help unravel some of the universe’s biggest mysteries, from exoplanet habitability to dark energy.

Sign up to our free Launchpad newsletter for a voyage across the galaxy and beyond, every Friday