15// James Webb Space Telescope (JWST)

hey chat, sorry for not posting for almost 3 months I don't have an excuse honestly (its not like anyone cares anyway lmao) :p

I'm going to simply explain how the JWST works, if you want a more detailed explanation, click here: !!30 minute yt video!!

JWST launched 25th of December, 2021. Its mission should take around 5 to 10 years. So what are the goals of its mission?

The main goals of the JWST are: searching for the light of the first galaxies formed after the big bang, studying the life cycles of stars, and investigating the potential for life in planetary systems.

JWST focuses on infrared astronomy - if you don't know what infrared means, it is electromagnetic radiation, with waves longer than visible light (but shorter than microwave). You can see how it works in the image below: 

Infrared astronomy is useful for studying the universe since we are studying objects so far away and redshift (Doppler effect) occurs. You can also see through clouds of dust with infrared, and see stars that you can't see normally, as you can see in the image here:

JWST needs to be in temperatures under 50 Kelvin. To make sure the telescope stays in these temperatures, there's a sun shield (to shield it from the Sun). It also orbits at a second Lagrange point (L2), which is in the Earth's shadow. Lagrange points are points where the gravitational forces of two objects are balanced, and the third object (in this case JWST) basically stays in the same place without using a lot of energy (fuel). There are 5 Lagrange points, here's a map of them (not to scale): 

JWST is divided into 2 parts: the sun shield and the telescope itself. Let's talk abt the sun shield first. The sunshield reflects light and heat from the Sun, Earth, and Moon. It's made out of 5 thin layers, covered in aluminum. The sun shield is designed to fold 12 times because it couldn't fit into the rocket, and had to unfold in space. The sun shield of course blocks the view of the telescope, and it can only see about 40 percent of the sky at a time. The sun shield also creates a shadow for the telescope, similar to our night at Earth, which obviously makes it easier to look at stars far away. This is a picture of JWST just so we know what we are talking abt:

The telescope itself uses a three-mirror anastigmat. The primary mirror is made out of 18 hexagon pieces, and each of them can be controlled. I hope this will help you understand how it works:

I won't be explaining the optics, but I hope you learned something!

correct me if I'm wrong on something or ask if you have any questions :D

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