Post by Andrei Tchentchik on Aug 14, 2020 10:37:31 GMT 2
(.#462).- Here's why the James Webb Telescope is worth the wait…
Here's why the James Webb Telescope is worth the wait…
By: Brice Louvet, science editor
January 4, 2020, 5:51 p.m.
Credits: Wikimedia Commons / Kevin Gill
NASA's James Webb Telescope is slated to launch in March 2021, after years of delay and billions of dollars spent outside the budget. But we don't hold it against him. This instrument will revolutionize our approach to the Universe.
The James Webb Telescope, which was originally supposed to be launched in 2018, is still pending. Significant technical and (especially) budget problems forced mission officials to postpone its launch several times, causing NASA’s budget to explode. We are currently at $ 9.7 billion, while the total cost of the project was estimated at $ 4.5 billion.
Time wasted and money wasted? No, because this observatory will give us access to the most distant corners of the Universe. And more.
Specialized in infrared
Since its first sketches, it has been announced as the “successor” of the Hubble telescope. But this is not really the case. The latter is mainly an optical instrument. It is, in a way, a gigantic eyeball orbiting the Earth. JWT will focus entirely on infrared wavelengths, which are largely invisible to human eyes.
These capabilities require a lot of investment, both intellectual and financial. Indeed, it is very complicated to “see the cosmos” in infrared from the ground because of the light pollution emanating from the heat. Everything from the human body to the planet returns heat. Even the telescope itself, kept at room temperature, shines in the infrared.
This is why the James Webb Telescope will be sent far from Earth, about 1.5 million kilometers away. But here again, the instrument will have to face a very important source of heat: the Sun.
To deal with it, NASA engineers imagined a 22-meter long by 11-meter wide space umbrella, made up of five very thin layers of extremely reflective materials. A gigantic “sun visor” therefore, which should keep the telescope in the shade, at temperatures around -223 ° C.
Some of the instruments on board will also be kept cool (-258 ° C) thanks to an active cooling system.
The fully assembled James Webb Space Telescope.
Credits: NASA / Chris Gunn
From the primitive Universe to exoplanets
Once in place, the JWT will finally begin its work. It should normally focus on the early universe, when our cosmos was only a few hundred million years old.
He will then be able to “see” the first stars and galaxies appear and answer certain questions that have remained unanswered for the moment: why and how are these objects formed? What relationships do they have with their supermassive black holes? What triggers star formation?
It will also be about studying the protoplanetary discs, hopefully betraying the presence of new worlds. The telescope will also be able to take pictures of any object orbiting the nearest stars. It will also be able to measure the molecular composition of the atmospheres of exoplanets, thus making it possible to estimate their degree of habitability.
Where do we come from ? Where are we going ? Are we alone in the universe ? Finally, thanks to the James Webb Telescope, we may soon be able to answer some of the most basic questions in the Universe. That’s why it’s worth the wait.
F I N .
Here's why the James Webb Telescope is worth the wait…
By: Brice Louvet, science editor
January 4, 2020, 5:51 p.m.
Credits: Wikimedia Commons / Kevin Gill
NASA's James Webb Telescope is slated to launch in March 2021, after years of delay and billions of dollars spent outside the budget. But we don't hold it against him. This instrument will revolutionize our approach to the Universe.
The James Webb Telescope, which was originally supposed to be launched in 2018, is still pending. Significant technical and (especially) budget problems forced mission officials to postpone its launch several times, causing NASA’s budget to explode. We are currently at $ 9.7 billion, while the total cost of the project was estimated at $ 4.5 billion.
Time wasted and money wasted? No, because this observatory will give us access to the most distant corners of the Universe. And more.
Specialized in infrared
Since its first sketches, it has been announced as the “successor” of the Hubble telescope. But this is not really the case. The latter is mainly an optical instrument. It is, in a way, a gigantic eyeball orbiting the Earth. JWT will focus entirely on infrared wavelengths, which are largely invisible to human eyes.
These capabilities require a lot of investment, both intellectual and financial. Indeed, it is very complicated to “see the cosmos” in infrared from the ground because of the light pollution emanating from the heat. Everything from the human body to the planet returns heat. Even the telescope itself, kept at room temperature, shines in the infrared.
This is why the James Webb Telescope will be sent far from Earth, about 1.5 million kilometers away. But here again, the instrument will have to face a very important source of heat: the Sun.
To deal with it, NASA engineers imagined a 22-meter long by 11-meter wide space umbrella, made up of five very thin layers of extremely reflective materials. A gigantic “sun visor” therefore, which should keep the telescope in the shade, at temperatures around -223 ° C.
Some of the instruments on board will also be kept cool (-258 ° C) thanks to an active cooling system.
The fully assembled James Webb Space Telescope.
Credits: NASA / Chris Gunn
From the primitive Universe to exoplanets
Once in place, the JWT will finally begin its work. It should normally focus on the early universe, when our cosmos was only a few hundred million years old.
He will then be able to “see” the first stars and galaxies appear and answer certain questions that have remained unanswered for the moment: why and how are these objects formed? What relationships do they have with their supermassive black holes? What triggers star formation?
It will also be about studying the protoplanetary discs, hopefully betraying the presence of new worlds. The telescope will also be able to take pictures of any object orbiting the nearest stars. It will also be able to measure the molecular composition of the atmospheres of exoplanets, thus making it possible to estimate their degree of habitability.
Where do we come from ? Where are we going ? Are we alone in the universe ? Finally, thanks to the James Webb Telescope, we may soon be able to answer some of the most basic questions in the Universe. That’s why it’s worth the wait.
F I N .
