The heat shield that needed to be developed consists of five layers of a special material called Kapton. The outer layer, which will be the only one to face direct sunlight, is 0.05 millimeters thick. The other four are twice as thin, about the thickness of a human hair. They will protect scientific instruments from the sun’s heat.
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The telescope will be permanently shielded with a shield towards the Sun, and its giant mirror and detection devices will be on the opposite side. On the “hot” side of the device, the temperature can rise up to 110 degrees Celsius, but the other side must keep the temperature below minus 223 degrees Celsius for the observatory to function successfully.
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Let us recall the process of stretching the layers of the JWST sun visor. The first layer has a thickness of 50.8 μm and the other four only 25.4 μm. The temperature of the “hot” side of the screen can reach up to 110 ° C, while on the “cold” side it is ideally -237 ° C (and never more than -223 ° C). pic.twitter.com/jmbuv5LKlH
– Michal Vaclavik (@Kosmo_Michal) January 5, 2022
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“On the ‘cold’ side of the screen, the temperature should ideally be -237 ° C,” added space specialist Michal Václavík from the Czech Space Office on his Twitter.
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Gradual “unpacking” along the way
The telescope is too large to fit the rocket as a whole, so it traveled folded and should be assembled “on the spot.” The development of the heat shield was considered to be the most difficult of the individual steps.
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The device is still on its way to its orbit, which will be 1.5 million kilometers from Earth and which the device will reach sometime in late January. One hundred engineers who work in Baltimore, USA, are involved in its gradual “unpacking”.
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“When someone asks me what wakes me up at night, I answer that it is developing a heat shield. We’ll rest as we spread the fifth layer, ”said NASA’s chief of staff, NASA’s NASA space agency, as the shield began to expand. According to AFP, three layers were developed last week and the remaining two on Tuesday, January 4.
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The next step will be to place two mirrors, first the smaller one, the secondary one and then the main one. It is covered with gold and has a diameter of 6.6 meters. The mirrors will be completely adjusted when the device reaches its orbit.
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However, the partial disassembly of the apparatus will continue during Wednesday. The optical part of the telescope (OTE) comes next. Around 16:00 CET, the unfolding of the SMSS beams holding the secondary mirror and its placement in the working position will begin.
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(1/2) The dismantling of the James Webb Space Telescope (JWST) will continue today. The optical part of the telescope (OTE) comes next. Around 16:00 CET, the unfolding of the SMSS beams holding the secondary mirror and its placement in the working position will begin. SMSS has the shape of a tripod when unfolded. pic.twitter.com/zqxCeSpXs4
– Michal Vaclavik (@Kosmo_Michal) January 5, 2022
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Humans have not yet launched a more powerful telescope into space. Unlike the Hubble Telescope, Webb will not observe the universe from the Earth’s low orbit, but from the so-called second Lagrange point (L2), where the gravitational forces of the Earth and the Sun balance. As a result, the telescope can maintain a stable position while being far enough away from the Sun to capture the very faint infrared radiation that arrives at its mirrors from the first stars and galaxies to form 13.5 billion years ago.
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The telescope can help test Hawking’s controversial theory
In addition, new research suggests that we will soon be able to test one of Stephen Hawking’s most controversial theories. The James Webb Telescope should provide the much-needed data.
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In the 1970s, Hawking formulated the idea that dark matter, the invisible substance that makes up most of the matter in the universe, may have come from black holes created in the early moments of the Big Bang. Now, three astronomers have come up with a theory that explains not only the existence of dark matter, but also the formation of the largest black holes in the universe, Space.com reported.
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“What I find extremely exciting about this idea is how it elegantly combines the two really challenging problems I’m working on – exploring the nature of dark matter and the formation and growth of black holes – and solving them in one fell swoop,” said the co-author of the study, an astrophysicist. Yale University Priyamvada Natarajan.
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Dark matter makes up over 80 percent of all matter in the universe, but in no way directly interacts with light. It just floats, is massive and affects the gravity inside the galaxies. The idea that black holes can be responsible for these elusive things is tempting. After all, black holes are dark, so filling the galaxy with black holes could theoretically explain all the observations of dark matter.
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Unfortunately, in the modern universe, black holes only form after massive stars die and collapse under the weight of their own gravity. Creating black holes thus requires many stars, which requires a lot of ordinary matter. Scientists know how much ordinary matter there is in space from calculations of the early universe, where the first hydrogen and helium were formed. But there is not enough ordinary matter to create all the dark matter that astronomers have seen so far.
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And then Hawking came. In 1971, he suggested that black holes formed in the chaotic environment of the earliest moments of the Big Bang. Back then, pockets of matter could spontaneously reach the densities needed to create black holes and flood the universe with them long before the first stars flashed. Hawking suggested that these “primordial” black holes may be responsible for dark matter.
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The idea was revived in 2015, when the Laser Interferometer Gravitational Wave Observatory (LIGO) in the USA discovered its first pair of colliding black holes. These two black holes were much larger than expected, and one way to explain their large mass was that they formed in the early universe, not in the hearts of dying stars.
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In the latest research, Natarajan, Nico Cappelluti of the University of Miami and Günther Hasinger of the European Space Agency (ESA) delved into the theory of primordial black holes and explored how they could explain dark matter and possibly solve other cosmological problems. In the new work, they assume that the original black holes weighed 1.4 times the mass of the Sun. They created a model of the universe that replaced all dark matter with these low-mass black holes, and then sought observational clues that could confirm or rule out this model.
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Researchers have found that primordial black holes could play a major role in the universe by laying the foundations for the first stars, the first galaxies, and the first supermassive black holes. “The original black holes, if any, could be the germs that made up all the giant black holes, including the one in the center of the Milky Way,” Natarajan said.
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So far, this is just a model that could be tested relatively soon. The Webb Telescope is specially designed to answer questions about the origin of stars and galaxies. And the next generation of gravitational wave detectors, most notably ESA’s upcoming Laser Interferometer Space Antenna (LISA), is ready to uncover much more about black holes – including the original ones, if any.
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