![]() The results have important implications for theories of how galaxies have evolved since the beginning of the universe 15 billion years ago. The Hubble pictures reveal that star-forming galaxies were far more prevalent in the clusters of the younger universe than in modern clusters of galaxies near us today. Looking far away and far back in time, NASA's Hubble Space Telescope (HST) has found some suspected ancestors of today's galaxies. Four Successful Women Behind the Hubble Space Telescope's Achievements.Characterizing Planets Around Other Stars.Measuring the Universe's Expansion Rate.The JWST will focus on collecting light in the infrared range of the electromagnetic spectrum of light, and is expected to be able to quite literally ‘see back in time’ to events such as galaxy formation just a few hundred million years after the Big Bang. The Universe has been expanding since the big bang, with objects further away from us moving away faster, and so as light travels towards us from distant objects it gets ‘red-shifted’: relative increases in wavelength. ![]() Essentially, the greater the distance between us and an object in the universe, the ‘younger’ it appears, because the light takes longer to reach us. The JWST works by its emphasis on infrared astronomy, based on the phenomenon of cosmological red shift. “The main goal of the JWST is to observe distant objects in the universe, beyond the reach of current instruments” It is expected to detect stars nearly 300 million years older that those currently detected by the HST. The galaxy existed 480 million years after the Big Bang (for context, the Big Bang is estimated to have occurred 13.8 billion years ago). The Hubble telescope, back in 2011, identified a galaxy of blue stars approximately 13.2 billion light years away: a record at the time. The main goal of the JWST is to observe distant objects in the universe, beyond the reach of current instruments. Furthermore, the JWST is not fully serviceable in the same sense as the HST, but a docking ring included in its design means that other spacecraft will be able to visit it as needed. Fewer orbital corrections are needed to maintain the desired orbit for satellites at such points, making them ideal for the placement of objects such as the JWST. ![]() Lagrangian points refer to specific points of equilibrium for an object with a relatively small mass under the influence of two larger orbiting bodies (the Earth and the Sun, in this case). It is designed to operate at lower temperatures than the HST, and further away from the Earth: specifically, at the L2 Lagrangian point. ![]() But it is not just ‘the next Hubble telescope’. The result of international collaboration between NASA, the European Space Agency and the Canadian Space Agency, the JWST is formally recognised as the successor of the HST. The James Webb Space Telescope (JWST), launched on Christmas Day from Kourou, French Guiana has, as of January 9th 2022, been fully deployed, and aims to push the boundaries of our knowledge even further. While the HST paved the way for groundbreaking discoveries, it still ultimately had its limitations, extending even beyond its lifespan. “It is not just ‘the next Hubble telescope’” It is unsurprising, therefore, that in 2009 NASA implemented technology on the HST to facilitate its controlled and safe de-orbit. If it is left to do so on its own accord, and subsequently make an uncontrolled descent, there would likely be damage and possibly risk to human life. But there is a limit to how long the HST will be able to function: its orbit around the Earth will eventually decay due to drag, meaning that it will eventually pass into the Earth’s atmosphere again. ![]() Since then, it has remained in space, with Space Shuttle missions launched to carry out essential maintenance procedures and replacements. The Hubble Space Telescope (HST), launched into low Earth orbit in 1990, was a revolutionary step in astrophysics, facilitating breakthroughs such as the determination of the rate of expansion of the universe. ![]()
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