詹姆斯韦伯太空望远镜 (JWST) will specialise exclusively in infrared astronomy to study early 宇宙. It will search for optical/infrared signals from the early stars and galaxies formed in the 宇宙 soon after the Big Bang for a better understanding of the formation and evolution of galaxies and the formation of stars and planetary systems. 西太平洋标准时间 will also study planetary systems and the origins of life. The much-awaited 西太平洋标准时间 is now scheduled to be launched on 18 December 2021.
Usually, one focusses a telescope at a target to observe. But at times you deliberately focus on nothing and that change the course of a field of study. Decision to focus 哈勃 space telescope on nothing in the hitherto unexplored fields in the sky was one such incident that changed the course of astronomy.
在众多具有里程碑意义的成就中 哈勃 Space Telescope (HST), the deep field images taken over the course of 10 days in 1995 when it captured about 3000 images of galaxies at different stages of stellar evolution has revolutionised astronomy and changed our understanding of the 宇宙.
These deep field images were formed by the light that had travelled from the remotest locations of the 宇宙 for billions of light years through the expanding 宇宙 and had reached Earth now to be captured by the 哈勃 telescope after originally emanating from the early stars and galaxies formed soon after Big Bang about 13 billion years ago. So, as such deep field images denoted early stars and galaxies as they were then billions of years ago. This was truly remarkable feat.
But, this technique of capturing primordial optical signals for developing understanding of early 宇宙 could not be an effective methodological tool due to the fact discovered in 1929 by Edwin 哈勃 该 宇宙 is expanding and all galaxies are moving away from each other as evidenced by the redshift of 星系’s spectrum to higher wavelengths in infrared (IR) region. But the 哈勃 telescope is equipped to observe in UV, visible and near-infrared region hence the need for an exclusive infrared 天文台 在太空。
詹姆斯韦伯太空望远镜 (JWST) is thus a successor to the 哈勃 space telescope (HST) in the sense that the 詹姆斯·韦伯 telescope aims to carry forward the 哈勃 望远镜在早期研究领域的遗产 宇宙. 西太平洋标准时间 will operate exclusively in infrared astronomy and has following four key goals:
由于这些原因， 西太平洋标准时间 needed to be different from 哈勃 telescope in design and operation. It is a reflecting telescope designed to capture near-infrared radiations from ultra-deep fields with a large origami-style mirror that makes it 100 times more powerful than 哈勃。 事实上， 西太平洋标准时间 is the largest space telescope ever. To maintain its unprecedented infrared sensitivity, 西太平洋标准时间 has protection from infrared contamination from sun through a highly effective 5-layer sunshield. Further, to help maintain its very low operating temperature of 50 Kelvin (-223° C or -370° F), JWST will be placed in an orbit around the sun in the cold shadow of Earth all the time near the second Lagrange point (L2) of the Earth-Sun system at a distance of about 1.5 million km from Earth.
的位置 西太平洋标准时间 near far off Sun-Earth system L2 orbit means, unlike 哈勃 telescope which received several repairs and maintenance in the space, 西太平洋标准时间 will be completely on its own after launch therefore there is no scope of any error at all. Perhaps this explains why launch of 西太平洋标准时间 is almost eternally delayed.
现在， 西太平洋标准时间 is planned to be launched on 18 December 2021.
As on 02 November 2021, 西太平洋标准时间 has already safely arrived at its launch site in French Guiana and the technical team is preparing for lift off on 18 December.
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来源：
- NASA 2021. 韦伯望远镜——美国宇航局詹姆斯韦伯太空望远镜的发射之路和超越之路。 02 年 2021 月 XNUMX 日发布。可在线获取： https://www.nasa.gov/feature/goddard/2021/the-road-to-launch-and-beyond-for-nasa-s-james-webb-space-telescope
- 美国宇航局。 JWST – 关于韦伯的一般问题。 可在线获取 https://www.jwst.nasa.gov/content/about/faqs/faq.html
- 美国宇航局。 JWST – 关键事实。 可在线获取 https://jwst.nasa.gov/content/features/keyFactsInternational/
- 欧空局。 科学与探索。 韦伯——看得更远。 可在线获取 https://www.esa.int/Science_Exploration/Space_Science/Webb
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