What is the James Webb Telescope?
Tamima Rashid
Embedded Files
On December 25, 2021, the James Webb telescope was launched into space. This moment had been in the making for over twenty years, with a total cost of 10 billion dollars. According to Bill Nelson, its main purpose is to acquire “a better understanding of our universe and our place in it: who we are, what we are, the search that’s eternal.” The objective of the James Webb telescope is to see farther into the universe than we ever have before, a mere hundred million years from when the Big Bang occurred. This is all possible because of how space and time interact with each other. For example, when we see the sun, we are seeing it as it was eight minutes ago, because that is the time it takes for sunlight to reach the Earth. Similarly, the farther the James Webb telescope can see, the farther into the past humans will be able to peer. This telescope will change the way we see the universe permanently.
The Webb telescope was made to succeed the Hubble telescope, which orbits the Earth. In contrast, the James Webb telescope will peer far beyond that, to a spot where the Sun’s gravitational forces and the Earth’s orbital motion balance each other so that the telescope can easily hover there. This is called a Lagrange Point. The Hubble could see mostly the same type of light as visible to humans, but according to CNN - “Webb will act as an infrared detective, detecting light that is invisible to us and revealing otherwise hidden regions of space.” This telescope will be able to see 13.7 billion years into the past.
This new telescope will reach farther than ever before - too far to be repaired. For this reason, every detail of the James Webb space telescope has been inspected carefully. The most striking piece of this telescope is its plate of hexagonal golden mirrors, which is made of beryllium coated in gold. Beryllium was chosen because despite it being lightweight, it is six times stiffer than steel.
To complete its actual function as a mirror, the beryllium is coated in gold. Gold is particularly reflective to infrared light while also being resistant to tarnishing. The most impressive fact about this device is that, unlike the Hubble, which needed the help of astronauts to be fixed, the JWST is programmed to have each of its hexagonal plates re-adjust themselves relative to the small parallel mirror. This smaller mirror’s primary job is to reflect light from the primary mirror into the ISIM (Integrated Science Instrument Module).
The next notable feature is the telescope’s sun-shield, about the size of a tennis court. It is five layers of silver slabs located under the mirrors. Its purpose is to keep the telescope at the temperature of -233 degrees Celsius which it needs to be. To assemble this shield, they used Kapton—a type of plastic film that can withstand immensely cold temperatures–wrapped in five layers of aluminum that are as thin as 0.25 millimetres. Aluminum was used because of its reflective property. When heat travels through this multilayered shield, most of it will escape through the sides. The little that remains will travel to the next layer, repeating this process.
The launch of the James Webb Space telescope is sure to be the beginning of big discoveries. The possibilities are endless. Best said by NASA astrophysicist Amber Straughn, “We have all these specific plans, these specific things we want to learn, but I think that the most awesome thing we’ll end up learning with this telescope we haven't even thought of yet. Because when we increase our technology by an extreme amount like this, I think it's inevitable that we'll find something that completely surprises us and causes us to rethink how we understand the universe.”
Page layout by Harry James Gonzales
Page updated
Report abuse