On January 8, 2022, arguably humankind’s greatest engineering achievement came to fruition about a half a million miles behind our planet. After 20 years in development, $10 billion spent, and 14 nail-biting days of exquisite hi-tech origami in space, the James Webb Space Telescope (JWST) was fully deployed.
After successfully launching from the Guiana Space Centre in French Guiana on Christmas Day while folded-up in the fairing of the Ariane 5 rocket, engineers remotely controlled 50 moving parts and 178 release pins. Everything had to happen correctly, in sequence, to put Webb in its final configuration. It worked.
This Monday, January 24, after a 30-day journey into space, Webb arrives at its final destination. A dream realized? Not yet. This is what happens next.
What is Webb?
Webb is the biggest and the most advanced space observatory ever constructed. About 100 times more powerful than Hubble, Webb is the size of a 70-foot tennis court. Its massive 21.6-foot primary mirror (to Hubble’s 8-foot primary mirror) is made from super-strong beryllium and comprises 18 hexagonal segments.
Each segment is covered in gold, which is perfect for reflecting infrared light. And that’s the main difference between Webb and Hubble. Unlike Hubble, which looks at the universe in visible and ultraviolet light, Webb captures ancient, stretched infrared light. That, coupled with its larger mirror, means it can look further back in time than astronomers have ever been able to do before.
Will Webb really look back in time?
All telescopes are time machines. The light from every single star you see is old and has travelled very far to reach you. Even the Sun’s light is 8 minutes and 20 seconds old. The brightest star in the night sky, Sirius, is 8.6 light-years away. That means its light has travelled for 8.6 years at 186,000 miles per second to reach your eyes.
Every photon Webb will detect is old light, but since it’s an infrared telescope it will detect the very oldest, most ancient light. Infrared light is electromagnetic radiation with wavelengths longer than visible light, so it is imperceptible to the human eye.
The very oldest light in the universe – emitted soon after the Big Bang 13.8 billion years ago, when the first stars and galaxies formed – has been stretched by the expansion of the Universe, so it is deeply red. So red in fact that it falls off the visible light spectrum entirely and into the infrared spectrum.
Webb will be able to study those very first stars and galaxies a few hundred million years after the Big Bang, something no other telescope has been able to do. That is why Webb was built.
Where is Webb?
The Webb telescope is currently here. Although it’s too small and dim to see with the naked eye, look out at night and Webb will be out there. It’s currently in the constellation of Monoceros, slightly east of…