🌍 Recently, astronomers celebrated a very important birthday... that of the James-Webb telescope. A birthday that deserved to be celebrated, because it is not a telescope like the others! Developed by NASA, with the participation of the European Space Agency and the Canadian Space Agency, the James-Webb is nothing less than the largest and most expensive telescope at the time of its launch. The James-Webb was launched on December 25, 2021. In one month, the telescope reached its orbit, 1.5 million km from Earth. After a first image published in July 2022, the James-Webb revealed images all more impressive than the other, which allowed astronomers to make beautiful discoveries.
🔥 As a reminder, videos are published on SUNDAYS at 6:00 PM.
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💥 BEST JAMES WEBB DISCOVERIES: - The launch of the James-Webb telescope serves many purposes. During its mission, the James-Webb will look to the earliest galaxies, those that appeared just after the Big Bang, to observe their diversity and understand their formation. It will also study exoplanets and their atmospheres, looking for biosignatures that could indicate extraterrestrial life. It will also observe the black hole Sagittarius A*, located at the center of the Milky Way, in order to complete the images produced by an array of telescopes in May 2022.
A little more than a year after its launch, the James-Webb telescope has already exceeded all expectations! It has revealed unprecedented images of nebulae, for the first time visible with such quality, of very distant galaxies and stars. It also provided unprecedented images of planets in our solar system, such as Jupiter and Neptune, which had never been photographed with such precision! Astronomers are pleasantly surprised: the James-Webb has not encountered any technical problems and its instruments are even more efficient than expected!
The first image of the James-Webb telescope was unveiled on July 12, 2022. It is a photograph of the galaxy cluster SMACS 0723 as it was 4.6 billion years ago. Described by NASA as "the deepest and sharpest infrared image of the distant Universe to date," this image is historic. Yet it's not really the deepest image ever, since the Planck satellite photographed the cosmic microwave background, the oldest photons in the universe, in 2013. Returning to the first James-Webb image, SMACS 0723 is a compact cluster of galaxies located more than 4 billion light years from Earth. The photographed area is actually no larger than a grain of sand! Amazing, isn't it? This image is impressive for its precision (19 galaxies can be seen instead of the 5 observed by Hubble) but not only: it also illustrates an effect of general relativity described by Albert Einstein, the gravitational lens. The gravitational lensing effect is the deflection of light by a mass (planet, galaxy or cluster of galaxies). More concretely, when a very massive celestial body is between an observer and a distant light source, the gravitational lens deflects the light rays that pass near it and distorts the images that the observer receives. This first James-Webb image, because it is sharper and more detailed than any Hubble image, may help scientists measure the ages and masses of star clusters in distant galaxies in order to build more accurate models of the galaxies that existed in the "cosmic springtime"
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🎬 On the agenda today: - 00:00 - Introduction - 01:35 - Creation and launch of the James Webb Telescope - 04:30 - Background to the creation of the James Webb - 05:28 - Objectives of the James Webb - 06:14 - James Webb, Complementing the Work of Hubble - 09:28 - What are we trying to observe? - 09:55 - How does James Webb work? - 10:55 - Discoveries of the James Webb telescope - 12:05 - The first image of the James-Webb telescope - 14:38 - Wasp 39-b - 18:08 - The Carina nebula - 21:01 - The Orion Nebula - 23:27 - The Tarantula Nebula - 25:35 - The planetary nebula of the Southern Ring - 28:16 - Ancient galaxies - 35:55 - The 2nd most distant galaxy: Glass-z13 - 38:50 - The ghost galaxy M74 - 41:27 - The Wagon Wheel Galaxy - 43:18 - Stephan's Quintet - 46:19 - The pillars of creation - 48:53 - Jupiter and its auroras - 52:34 - Neptune and its moons - 56:04 - The exoplanet HIP 65426 b in the mid-infrared - 57:26 - LHS 475 b, an Earth-like exo-planet - 01:00:55 - The cosmic hourglass - 01:02:30 - The expectations of the James Webb Telescope
