Effects of the James Webb Telescope

By Alice Deyell, ’26

The James Webb telescope is the largest and most powerful space telescope ever built that can see so far back into our universe that it can nearly see the Big Bang. It can take images of the first-ever galaxies, observe objects in our solar system and beyond, and examine the atmospheres of exoplanets. The telescope was launched on Christmas morning, 2021 from the ESA’s spaceport in French Guiana. James Webb had to make its way to the second Sun-Earth Lagrange point, a gravitationally stable location in space. It reached its permanent home on January 24, 2022. The telescope became active in July 2022, and now, just over a year since its launch, we are already learning new and amazing things from it. 

Firstly, the James Webb space telescope (JWST) has taken some amazing pictures of far-off galaxies and stars with a new level of sensitivity we’ve never seen before. As the JWST can detect infrared cosmic light, wavelengths just longer than the human eye can see, new exoplanets and galaxies are being found.  For example, the JWST took a picture of Pandora’s cluster, which is made of three galaxy clusters merging into one. The picture needed a long exposure time to capture the faint light of old galaxies in the cluster, which are easier to see due to gravitational lensing, where the cluster acts like a magnifying glass. 

Another vital part of Webb’s infrared sensitivity is centred around extraterrestrial life outside of our solar system on exoplanets. Thanks to the JWST we can now detect the chemicals life is dependent on, or chemicals made by life in the atmospheres of exoplanets. It does this by detecting tiny decreases in the brightness and precise colours of light to tell what gas molecules are in the atmosphere. While the Hubble could detect things like water vapour, the Webb can detect a whole new array of molecules that will hopefully narrow down our search for alien life. WASP-96b is a confirmed gas giant exoplanet in the Milky Way, 1150 light years away from Earth. One of Webb’s instruments, the Near-Infrared Imager and Slitless Spectrograph (NIRISS) detected carbon dioxide in this planet’s atmosphere and will be able to detect oxygen and methane in others. If we can find exoplanets in the habitable zone of their stars with gases like methane, which are mostly produced by life here on Earth, or oxygen, which is essential to life, we will be able to have a more precise guess about the whereabouts of extraterrestrial life.

Finally, the JWST’s capacity to see far into the past is one of its most game-changing features. Before, astronomers have just been looking at simulated data of what happened at the start of the universe around the Big Bang. Now, the JWST can show us the formation of the first galaxies less than 400 million years after the Big Bang. This is possible due to the scale of the universe, making light take a long time to travel through it. Light years are the unit of measurement in space since light is the fastest thing in the universe. Even light can’t move that quickly around the universe, so if you look at something 13.5 billion light years away, you will see it as it was at the start of the universe. Everything we see in space is just a ghost of what it once was, as light takes a certain amount of time to reach the Earth.

While we’ve seen some amazing things, the JWST has only been around for a year, and who knows what it will discover in the next 5-10 years. While some of the scientific community were skeptical about this massive, expensive telescope, we have only just started to reap the many benefits of the James Webb Space Telescope.