After nearly 30 years of work, the James Webb Space Telescope is about ready for liftoff. The successor to the famous Hubble telescope was originally scheduled to launch on December 22, although that launch has been delayed to no earlier than December 24. When the space telescope launches aboard an Arianespace Ariane 5 rocket from the Guiana Space Center in Kourou, French Guiana, a new era of astronomy will begin.
Longtime DPReview reader, Dr. Kevin Hainline, and Smile Mountain have teamed up to make a video about the James Webb Space Telescope, outlining the telescope’s impressive features and technology, including its onboard imaging equipment. Hainline is a professor at the University of Arizona and a member of the James Webb Space Telescope (JWST) NIRCam science team.
In Hainline’s entertaining and informative video, he discusses what makes the James Webb Space Telescope special. Compared to the Hubble Space Telescope, which is itself an impressively-engineered space telescope that has produced many fantastic photos of deep space, the JWST’s larger mirror can capture over six times as much light.
There are four separate cameras aboard the JWST. The cameras are NIRCam, the one Dr. Hainline works on, NIRSpec, NIRISS and MIRI. Light travels through space and hits the telescope’s primary mirror. It is then reflected onto the smaller secondary mirror and then into the Aft-Optics System, subsystem and finally, the cameras. By the way, the JWST has been designed to see infrared light, which is why its primary mirror is gold, as gold reflects infrared light better.
There’s much to be learned about celestial bodies and space itself by observing in infrared light. You can also see through space dust using infrared light, which is critical when performing observations. The farthest galaxies can only be seen in infrared light because optical light undergoes red shift as the universe expands. Hubble cannot see as much in the infrared wavelength as the JWST can, so the new telescope will be able to see much farther. The JWST isn’t replacing Hubble, though, the two space telescopes will work together.
Dr. Hainline is one of the scientists that worked on designing the JWST’s NIRCam. It’s a challenging proposition and the camera’s design reflects the challenge by incorporating a sophisticated design and interesting components, including mercury cadmium telluride. It’s a crystal made using molecular beam epitaxy, which as Dr. Hainline says, is a fancy of way saying that the team needed to grow the crystals. The crystals can convert infrared light into electricity, allowing the infrared light gathered by the JWST to be turned into digital signals that can be read.
As Dr. Hainline’s video says, ‘The James Webb Space Telescope is about to change astronomy. Get ready for discovery.’ We’re very excited for the JWST to launch and capture its first science-quality images, which should be by the end of its third month in space. Thanks to it covering longer wavelengths of light than Hubble, the more sensitive JWST will be able to look further back in time, and we’re poised to learn a lot about the early universe and how stars and planets are forming today.
All images courtesy of NASA/ESA/CSA ASC