World’s Largest Space Telescope Is Complete, Expected to Launch in 2018

The construction of the James Webb Space telescope is finally complete after more than 20 long years, and following testing, the largest space telescope is presumed to launch within two years.  Sarah Lewin, who wrote “World’s Largest Space Telescope Is Complete, Expected to Launch in 2018,” explains what makes this telescope so special. JWST is being considered as the successor to the Hubble Space telescope. It contains eighteen large mirrors that will collect infrared light that will be sheltered behind  a tennis-court sized sun shield. John Mather, who worked on the project explained that JWST will be much more powerful than Hubble due to two reasons; The telescope has seven times the collecting area as Hubble, and is designed to collect infrared light. Our planet’s atmosphere glows in infrared, meaning that JWST would not work if placed on our planet. Unlike Hubble, JWST does not emit any heat, running at temperatures near absolute zero so it will not release any infrared light. The telescope will stay at a point called the Lagrange Point 2, which is directly behind Earth from the sun’s perspective.  The telescope’s infrared view will be able to pierce through cosmic dust allowing us to see the universe’s first galaxies as well as gaze on newly forming planetary systems. JWST is said to be so powerful that it would be able to spot a bumblebee at a moon distance away, both in reflected light as well as in the body heat of the bee. This is possible from the mirrors being as smooth as possible. The original launch date was set for 2014  at a cost of $5 billion but due to budget constraints it got postponed almost resulting in a cancellation of the project and a new cost of $8.7 billion. JWST is not intended to be repaired or worked on by humans whatsoever after launch, meaning that all the preparation and focusing must be done before its launch.

It’s shocking that this telescope has been under construction for over 20 years and now finally it is so close to being finished. Just based off this article, it seems like JWST will be able to find really interesting data and observations from our universe. What interested me most was the power of the telescope. The fact that it can find an object as small as a bumble bee as far away are the moon is sounds unbelievable. It sounds almost too good to be true. I am very curious to what astronomers and scientist will be able to find using this telescope. While reading about other information on the James Webb Space Telescope, I learned that it will be able to give us even greater information on the TRAPPIST-1 solar system and if their truly is water on some of the planets. This telescope does seem really risky though. The fact that it is not designed to be repaired seems a little iffy. If one thing were to go wrong after launch or if not set in focus correctly, it seems like it would be a major issue. If spending $8.7 billion on the project, one would think they should make it easily repairable if some unfortunate event were to occur. This article greatly relates to our 9th conceptual objective. Telescopes are used for us to see objects that are very far away, usually on objects that can’t be seen at all or observed with the naked eye. Refracting and reflecting telescopes make the object being observed to appear larger, or magnified. Refracting telescopes uses glass lenses, such as a magnifying glass, to help us see planets, stars, or whatever object better and more in depth. Reflecting telescopes on the other hand use mirrors to reflect an object back into the eyepiece but reflected in a way that it appears completely magnified. With Reflecting telescopes, the larger the mirrors, the larger images can be magnified. This is because the larger mirrors are able to collect more light compared to a telescope with much smaller mirrors that can only collect a fraction of the light. There are also Radio telescopes that collect electromagnetic radiation such as infrared, ultraviolet, or x-rays, and process an image out of it. The James Webb Space Telescope is technically two telescopes in one. Since it is using large mirrors to collect light, that means it is a reflecting telescope. The reason it has to be in space however, is because it is also a radio telescope, collecting infrared waves. 20170404_155116

As the picture from our lecture-tutorial notes shows, different wavelengths are affected differently when passing through our atmosphere affecting whether a telescope can be placed on land or in space. If JWST were only a reflecting telescope, it would be able to remain on Earth and operate to its fullest since visible light easily passes through our atmosphere and reaches the ground. However, because it also collects infrared waves, it can not be placed on the ground and must be in space. If JWST were to be placed on top of one of our tallest mountains their would be a chance that it would be able to collect some infrared data. Unfortunately it would not be great data and even the infrared waves from Earth’s heat would be more than enough to give the telescope bad readings. Because JWST is going to be in space out of Earths atmosphere, it will have very clear readings from stars or planets being observed without any interference giving it the best data. If JWST were to collect either x-rays, gamma, or UV rays instead, it would still be required to be placed in space to receive accurate readings. If it were to collect just visible light rays and radio waves, then the telescope would be able to stay on Earth with us and still receive the light waves needed. If our Earth did not have an atmosphere then astronomers would be able to place telescopes where ever they wanted and still have them work to their full potential.


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