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How does the camera work on the James Webb Space Telescope and looks that far? – Kieran G., 12 years, Minnesota
Imagine a camera that is so powerful that it can see light from galaxies that were formed more than 13 billion years ago. This is exactly the James Webb Space Telescope from NASA.
Since its start in December 2021, WebB circles more than a million miles from Earth and captures breathtaking images from Deep Space. But how does it actually work? And how can it see so far? The secret lies in his mighty cameras – especially in those who do not see the light as our eyes do.
I am an astrophysicist who examines galaxies and super massive black holes, and the WebB telescope is an incredible tool to observe some of the earliest galaxies and black holes in the universe.
When Webb takes a picture of a distant galaxy, astronomers like me actually see how this galaxy looked billions of years ago. The light of this galaxy has been traveling over space for billions of years to reach the mirror of the telescope. It is like a time machine contains snapshots of the early universe.
By using a huge mirror to collect old light, Webb has discovered new secrets about the universe.
A telescope that sees warmth
In contrast to normal cameras or even the Hubble world space telescope, which takes pictures of visible light, WebB is designed in such a way that they see a kind of light that is invisible to their eyes: infrared light. Infrared light has longer wavelengths than visible light, which is why our eyes cannot see it. With the right instruments, however, WebB can record infrared light in order to examine some of the earliest and distant objects in the universe.
Infrared cameras, such as night vision glasses, enable them to see the infrared waves that radiate from warm objects such as humans and animals. The temperatures for the pictures are in degree of fahrenheit. NASA/JPL-CALTECH
Although the human eye cannot see it, people can recognize infrared light as a form of warmth with special technologies such as infrared cameras or thermal sensors. For example, night vision glasses use infrared light to recognize warm objects in the dark. Webb uses the same idea to study stars, galaxies and planets.
Why infrared? If the visible light from distant galaxies moves across the universe, it extends. This is because the universe is expanding. This stretch turns visible light into infrared light. The most distant galaxies in space no longer shine in visible light – they glow in a weak infrared. This is the light webb that was created for detection.
A golden mirror to collect the slightest glow
Before the light reaches the cameras, it must first be collected by the enormous golden mirror of the WebB telescope. This mirror is over 21 feet wide and consists of 18 smaller pieces of mirror that match a honeycomb. It is excessive in a thin layer of real gold – not only to look chic, but because gold reflects the infrared light very well.
The mirror collects light from the profound space and reflects it in the instruments of the telescope. The larger the mirror, the brightly it can collect – and the further he can see. Webbs Mirror is the largest that has ever been started in space.
The 21-foot primary level of WebB, consisting of 18 hexagonal mirrors, is coated with a cladding of gold. NASA
Within the cameras: NCAM and Miri
The most important “eyes” of the telescope are two scientific instruments that look like cameras: Nircam and Miri.
Nircam stands for the near infrared camera. It is the main camera on webb and takes breathtaking pictures of galaxies and stars. It also has a coronagraph – a device that blocks the star light so that very weak objects can take pictures near bright sources, e.g. B. planets that circle the bright stars.
Nircam works by imagining it near the infrared light, the type, to which those who can almost see human eyes, and divides it into different wavelengths. This helps scientists not only learn what something looks like, but also what it is made of. Various materials in the room absorb and emit infrared light at certain wavelengths, creating a kind of unique chemical fingerprint. By examining these fingerprints, scientists can uncover the properties of distant stars and galaxies.
Miri or the infrared instrument recognizes longer infrared wave lengths that are particularly useful to recognize cooler and more dusty objects, such as: B. stars that still form in gas clouds. Miri can even help to find references to the types of molecules in the atmospheres of planets that could support life.
Both cameras are far more sensitive than the standard cameras used on earth. Nircam and Miri can recognize the smallest amounts of heat from billions of light years away. If you had webbs nircam as your eyes, you could see the heat of a bumblebee on the moon. It is so sensitive.
The first Tieffeldbild from Webb: The Miri picture is on the left and the Niscam picture is on the right. NASA
Since WebB tries to recognize weak heat from distant objects, it must keep itself as cold as possible. Therefore, it carries huge sun protection over the size of a tennis court. This five -layer sun shield blocks warmth of the sun, earth and even the moon and helps WebB to stay incredibly cold: -223 degrees C approx.
Miri has to be colder. It has its own special refrigerator, which is known as a cryoc old to keep it at almost -447 degrees F (-266 degrees C). If webb were still a little warm, his own heat would drown out the distant signals that are trying to recognize.
Transform spatial light into pictures
As soon as the light reaches the cameras of the WebB telescope, it hits sensors that are referred to as detectors. These detectors do not record regular photos such as a telephone camera. Instead, they convert the incoming infrared light into digital data. This data is then sent back to earth, where scientists process them into full pictures.
The colors we see in webbs pictures are not what the camera “sees” directly. Since the infrared light is invisible, scientists assign colors of different wavelengths to understand what is in the picture. These processed images show the structure, age and the composition of galaxies, stars and more.
By using a huge mirror to collect invisible infrared light and send it to super cold cameras, we can see galaxies that have formed shortly after the universe began.
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This article will be released from the conversation, a non -profit, independent news organization that brings you facts and trustworthy analyzes to help you understand our complex world. It was written by: Adi Foord, University of Maryland, Baltimore County
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Adi Foord does not work for a company or an organization that benefits from this article and have not published any relevant affiliations about their academic appointment.
