You are looking at the golden mirrors of the biggest and the most complex Telescope built
to date: the James Webb Space Telescope.
You are looking at a $10 billion time machine that will take us to the edge of the universe, revealing how the universe looked just 100 to 250 million years after the big bang, helping us understand the formation of the first galaxies, and, most importantly, redefining our current understanding of the cosmos. You are looking at the largest and the most powerful space telescope built to date, the James Webb Space Telescope.
But why is it being referred to as a time machine? What excites you about Webb?
When you go to a place away from city lights and look up at the dark skies, you see stars, planets, a few galaxies, nebulae, and most importantly, the Milky Way. But the universe is not limited to what we see with the naked eye. It's home to a wide range of frequencies that go all the way from gamma rays to X-rays, ultraviolet rays, the visible region, infrared rays, microwaves, and finally, radio waves. As a result, our eyes can only see a relatively small portion of the spectrum.
The electromagnetic waves that we receive from distant stars and galaxies make up the most important way to study the cosmos. So the question is, if our eyes can't see the entire spectrum, how can we explore the vastness of the universe? Well, this is where advanced telescopes come to our rescue. Although we have launched many space telescopes that work in different regions of the spectrum, Hubble is the largest and the most versatile telescope of all. As a result, Hubble provided extensive insight into the universe, from objects as close as the Moon to the most remote galaxies.
Hubble, on the other hand, was especially interested in optical and ultraviolet wavelengths. In addition, it had some infrared capabilities. Still, when it comes to Webb, it's an Infrared Observatory that will mainly look at the universe in the infrared region, with some capacity in the red and yellow part of the visible spectrum. This means that Webb will help us observe even those distant areas that were out of Hubble's reach.
But how can an infrared telescope offer a deeper insight into the universe's past than an optical one? Why are infrared observations so important to astronomy?
Infrared radiations are simply the thermal signature of an object. Although we cannot see infrared radiation with our naked eyes, we can feel it. The heat from a stove, for example, is infrared radiation that we can feel with our skin. The electromagnetic spectrum shows that infrared rays have a longer wavelength than visible rays.
Are you still there with me?
The universe is full of regions that contain dust. Stars and planets that have just begun to develop are also shrouded under dust cocoons. Even when you look at the Milky Way, you'll notice dark dust clouds obscuring much of the galaxy. Because of its small wavelength, interstellar dust absorbs the majority of visible light. This offers a hindrance in having deep insight into the hidden regions engulfed in thick clouds of dust. But as I already told you, infrared rays have a longer wavelength than visible rays. Hence, infrared light can easily penetrate the dusty shroud to reach us.
The wavelength range of the James Webb Space Telescope will be 0.6 micrometers to 28 micrometers. This will allow Webb to gaze back 13.5 billion years in time, giving photographs of the early galaxies and spotting undiscovered planets near distant stars.
Are you wondering why I am saying it will look back in time?
Well, that's because light travels at a finite speed. For example, it takes 500 seconds for the light from the Sun to reach us. This means the Sun that we see is how it looked 500 seconds ago. From Earth, we can never know what the Sun looks like in real time. That's how everything we see in the sky is how it was in the past. No one knows what the universe currently looks like.
Space observatories are free from atmospheric absorption of infrared light and offer a far more accurate view compared to ground telescopes. However, there are several constraints by which infrared telescopes need to abide, and Webb is no different in this case. Infrared telescopes are specifically designed to minimize the amount of heat produced by them. Hence, Webb has to be kept at significantly low temperatures to make precise observations.
To protect Webb's mirror from the heat of the Sun, it will be kept at a temperature of minus 233°C. Furthermore, the telescope contains a five-layer solar shield the size of a tennis court that will eventually diminish the solar's heat by more than a million times. A successor to the Hubble and the Spitzer Space Telescopes, James Webb is expected to lead a new era of astronomical observations. For decades, the desire to view the creation of the first stars and galaxies has been a holy grail in astronomy. Since we are made of materials once processed in the cores of giant stars, it's like searching for our own origins.
If you are interested in studying astrophysics at home, make sure to check out our Basics of Astrophysics series, the link to which is given in the description. This series explains everything at the most fundamental level, from the EM spectrum to telescopes and from the birth of stars to the formation of black holes and galaxies.
How long will the James Webb telescope stay in space?
The James Webb Space Telescope, which is scheduled to launch in late 2021, is designed to have a minimum mission lifetime of 10 years. However, it is possible that the telescope could continue to operate beyond its expected lifespan if it remains in good condition and continues to produce valuable scientific data.
The telescope will be placed in a special orbit around the Sun, known as the second Lagrange point (L2), which is located about 1.5 million kilometers (930,000 miles) from Earth. This location will provide the telescope with a stable and unobstructed view of the cosmos, as well as protection from the heat and radiation generated by the Earth and the Sun.
The James Webb Space Telescope is expected to make groundbreaking discoveries in a variety of areas, including the study of distant galaxies, the formation of stars and planetary systems, and the search for life beyond our solar system. Its advanced technology and capabilities will allow astronomers to observe the universe in unprecedented detail and shed new light on some of the most fundamental questions in astronomy and astrophysics.
As with all space missions, the lifespan of the James Webb Space Telescope will depend on a variety of factors, including the health of its instruments, the availability of funding and resources for maintenance and operations, and the continued scientific value of the data it produces.
Why Does the James Webb Space Telescope Look Like That?
The James Webb Space Telescope (JWST) is one of the most advanced space telescopes ever built. It is set to launch on October 31, 2021, and is expected to revolutionize our understanding of the universe. However, one thing that many people are curious about is why the JWST looks the way it does. In this article, we will explore the design of the JWST and why it looks the way it does.
Introduction to the James Webb Space Telescope
The JWST is a partnership between NASA, the European Space Agency (ESA), and the Canadian Space Agency. (CSA). It is named after James E. Webb, who was the second administrator of NASA and played a key role in the Apollo program.
The telescope is designed to observe some of the earliest objects in the universe, including the first stars and galaxies. It is also designed to study the atmospheres of exoplanets and to search for signs of life beyond our solar system.
Design of the James Webb Space Telescope
The design of the JWST is based on a number of factors, including its scientific objectives and the environment it will operate. The telescope will be located at the second Lagrange point (L2), which is a stable point in space located approximately 1.5 million kilometers from Earth.
One of the key design elements of the JWST is its sun shield. The sun shield is made up of five layers of a special material that reflects sunlight and provides thermal insulation. The sun shield is designed to keep the telescope and its instruments cool, which is necessary for observing the infrared part of the spectrum.
Another important design element of the JWST is its primary mirror. The mirror is 6.5 meters in diameter, which is over three times larger than the Hubble Space Telescope's mirror. The larger mirror allows the JWST to collect more light, which is important for observing some of the faintest objects in the universe.
The primary mirror is also segmented into 18 hexagonal mirrors, which can be individually adjusted to maintain the telescope's focus. This design allows the JWST to achieve a much higher level of precision than the Hubble Space Telescope.
Why Does the James Webb Space Telescope Look the Way It Does?
The JWST looks the way it does because of its scientific objectives and the environment it will operate in. The sun shield is designed to keep the telescope and its instruments cool, which is necessary for observing the infrared part of the spectrum.
The primary mirror is also designed to be much larger than the Hubble Space Telescope's mirror, which allows the JWST to collect more light and observe fainter objects. The segmented design of the primary mirror allows for much greater precision than the Hubble Space Telescope, which is important for studying exoplanet atmospheres and other objects in the universe.
Conclusion
The James Webb Space Telescope is one of the most advanced space telescopes ever built, and it is set to revolutionize our understanding of the universe. The telescope's design is based on a number of factors, including its scientific objectives and the environment it will operate. The sun-shield and primary mirror are two key design elements that allow the JWST to achieve its scientific objectives. With its advanced capabilities, the JWST is poised to make groundbreaking discoveries that will change our understanding of the universe.
