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The Time Travel Machine In Telescope

The James Webb Space Telescope (JWST) made history by releasing its debut image. A gem-filled photo touted as the deepest picture of space ever taken.

Not only does the James Webb Space Telescope see farther into space than any observatory before it, but it has another trick with its mirrors.

It can look further into the past than any other telescope observing distant stars and galaxies that emerged 13.5 billion years ago, not long after the beginning of the universe as we know it.   

What Is The Past Telescope? 

The James Webb Space Telescope (JWST) launched six months ago with the goal of exploring the deep past of the universe. Located about a million miles from Earth, it is now fully functional after months of testing. NASA released the first images taken by JWST last night. JWST is his 20-year project involving NASA and the European Space Agency, the Canadian Space Agency, and hundreds of universities and other organisations.

According to NASA,  JWST, the most sensitive telescope ever commissioned, will "study every stage of the history of the universe, from within our solar system to the most distant observable galaxies of the early universe." That's what I mean.

JWST's light capture mirror is over 21 feet in diameter and approximately 270 square feet. It was folded like origami to fit in a rocket launched into orbit. The telescope must be cooled to approximately 380 degrees Fahrenheit to function properly. There is even an awning the size of a tennis court.  

What Is the Purpose Of Past Telescope? 

The  work started  on the proposal in February-March 2021 and submitted it in November 2021. Time has been given and observations are scheduled for April 2023.

As part of the proposal, we consider a very young star-forming region towards the galactic centre of the Milky Way. It's a light year.

The purpose  is to understand how star formation occurs in huge molecular clouds that are very dense and very massive. By studying the early stages of star and planet formation, we can learn about the formation and evolution of our own solar system. Our solar system is about 5 billion years old. What people are looking at is a very young stage of star formation, barely a million years old. It is interested in how the region is developing, and the characteristics of the youth. 

The Expectations From The JWST

Interesting results on the formation of stars and planets are expected in the  field of research. There are other proposals from other groups, such as taking deeper images of protoplanetary disks (dense disks of gas and dust) that form planets around young stars.

Some proposals deal with distant galaxies that formed shortly after the Big Bang The universe is about 13.8 billion years old. The first stars formed about 13.5 billion years ago. JWST will consider them. Galaxies formed in the early universe are predicted to be structurally different from those in the present universe. Galaxies in the present universe have different structures, but the first galaxies may have looked different.

JWST studies the evolution of galaxies. This is one of our biggest goals. Telescopes can see Mars and other planetary bodies in our solar system. Observe comets and asteroids to help you learn more about our solar system. There should be exciting results from exoplanet atmospheres.   

Features Of Past Telescope 

The James Webb Space Telescope has about half the mass of the Hubble Space Telescope. Webb has a gold-coated beryllium primary mirror 6.5 m (21 ft) in diameter, composed of 18 separate hexagonal mirrors. The mirror has a polished area of ​​26.3 m2 (283 sq ft), of which 0.9 m2 (9.7 sq ft) is hidden by secondary support braces for a total collection area of ​​25.4 m2 (273 sq ft). This is more than six times the collecting area of ​​Hubble's 2.4 m (7.9 ft) diameter mirror with a collecting area of ​​4.0 m2 (43 sq ft). The mirror has a gold coating that provides infrared reflectivity, which is covered with a thin layer of glass for durability. Web is designed primarily for near-infrared astronomy, but can also see visible orange and red light, and mid-infrared, depending on the instrument used. It can detect objects that are up to 100 times fainter than Hubble and objects that go back to redshift z20 (universal time about 180 million years after the Big Bang), long before the history of the universe. For comparison, the earliest stars are thought to have formed between z30 and z20 (100-180 million cosmological years), and the first galaxies were redshifted. It could be around or about 270 million cosmic years. Been formed. Hubble cannot go back any earlier than the very early reionization at about z11.1 (galaxy GN-z11, 400 million cosmic years). 

This design emphasises the near to mid-infrared for several reasons.

  • High redshift objects (very early distant objects) shifted visible radiation into the infrared, so their light is now only observable by infrared astronomy. 

  • Infrared light passes through dust clouds more easily than visible light. 

  • Colder objects such as debris disks and planets emit most in the infrared.

  • These infrared bands are difficult to study from the ground or with existing space telescopes like Hubble.  

Location And Orbit of Telescope  

Web operates in a halo orbit  circling around a point in space known as the Sun–Earth L2  approximately 1,500,000 km (930,000 mi) beyond Earth's orbit around the Sun. Its actual position varies between about 250,000 and 832,000 km (155,000–517,000 mi) from L2 as it orbits, keeping it out of both Earth and Moon's shadow. By way of comparison, Hubble orbits 550 km (340 mi) above Earth's surface, and the Moon is roughly 400,000 km (250,000 mi) from Earth. 

Objects near this Sun–Earth point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance with continuous orientation of its sunshield and equipment  toward the sun, earth and moon. Combined with its wide shadow-avoiding orbit, the telescope can simultaneously block incoming heat and light from all three of these bodies and avoid even the smallest changes of temperature from Earth and Moon shadows that would affect the structure, yet still maintain uninterrupted solar power and Earth communications on its sun-facing side. This arrangement keeps the temperature of the spacecraft constant and below the 50 K (−223 °C; −370 °F) necessary for faint infrared observations. 

Conclusion And Comparison With Other Telescope 

However, infrared telescopes have loopholes too. They need to be kept extremely cold, and the longer the infrared wavelengths, the colder they need to be. Otherwise, background heat from the device itself will overwhelm the detectors, effectively blinding them. This can be overcome by careful spacecraft design, especially placing telescopes in dewars containing very cold material such as  Liquid helium. The coolant evaporates slowly, limiting the lifetime of the instrument to months to at most years 

In some cases, spacecraft designs can keep temperatures low enough to enable near-infrared observations without a coolant supply. Extension of the Spitzer Space Telescope and Wide Field Infrared Survey Explorer missions. Another example is Hubble's Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument. This started with a block of nitrogen ice that had worn out years later, but was later replaced with a cryocooler that worked during STS-109 maintenance for the mission. Continuously. The James Webb Space Telescope is designed to be self-cooling without a dewar using a sunshield and radiator combination, and the mid-infrared instrument uses an additional cryocooler. 


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