James Weber Telescope: Touching Once Unreachable Corners in the Universe

The assembled James Weber telescope (including its "sunshade" and modular components) has been partially configured and will undergo further installation.

On January 6th, according to media reports, NASA's James Weber Telescope is currently scheduled for launch in March 2021. Prior to this, the project went through year after year of delays and billions of dollars in funding. Despite wasting a lot of time and money, this telescope will undoubtedly become the "king" of the infrared spectrum, allowing us to reach the once remote corners of the universe for the first time.

From the first galaxy formed after the birth of the universe to the possibility of the existence of extraterrestrial life, the James Weber Telescope, which costs about $9.7 billion, will be our only hope to further understand the universe.

Fearless of severe cold

Although the James Webb Space Telescope (JWST for short) is regarded as the "successor" of NASA's legendary Hubble telescope, this is not the case. Hubble is mainly an optical telescope that can capture light with a wavelength range similar to that of the human eye, only slightly expanding to the infrared and ultraviolet bands. In essence, the Hubble Telescope is like a huge eyeball orbiting in space, constantly sending back shocking images. And if your optic nerve is as powerful as it, you can see these amazing scenes yourself.

But the James Weber telescope is not. It will be observed entirely in the infrared band and will hardly touch the most "red" band visible to the human eye. In other words, it will study a universe that is almost invisible to humans.

One of the main reasons for the design of the James Weber telescope is the difficulty of conducting infrared band observations from the surface. If astronomers want to carry out accurate observation and measurement, they must ensure that the night sky is absolutely clear, but light pollution on the ground severely limits the observation conditions.

And infrared light pollution is everywhere, because any object with temperature will emit infrared light. The human body can generate 100 watts of infrared radiation. The Earth itself has high heat and appears bright and eye-catching in the infrared band. Even the telescope itself emits infrared radiation at room temperature.

In short, we are not completely unable to conduct infrared astronomical observations from the ground, but it is extremely difficult. Therefore, we chose to place the James Weber telescope in space.

Traveling far from home

To avoid the influence of Earth's infrared light, the James Weber telescope will operate at a distance of 1.5 million kilometers from Earth. Although far away from Earth, the sun is also a problem. You must have experienced the scorching sunlight outside in summer, which is infrared radiation. Even millions of kilometers away from Earth, the heat of the sun cannot be underestimated.

To this end, designers of infrared space telescopes can adopt several countermeasures. The most common method is to use an active cooling system to lower the temperature of the telescope to a level suitable for observing infrared wavelengths. This is a good method that has also been adopted in other infrared space telescopes before. But this also limits the working life of the telescope, as once the coolant is depleted, astronomical observations cannot continue.

Therefore, the James Weber telescope will take a unique approach and be equipped with an expensive giant "space umbrella". This' umbrella 'is 22 meters long and 11 meters wide, made of five layers of highly reflective material, each layer being less thick than the diameter of human hair. This huge "sunshade" will keep the telescope in shadow, with a temperature not exceeding -223 degrees Celsius, making it suitable for observation in the target infrared band.

However, an instrument mounted on the telescope will be cooled to minus 258 degrees Celsius using an active cooling system, which can receive longer wavelengths of infrared light.

The Power of Science

In summary, the James Weber Telescope is so massive that it cannot be carried by a single rocket. Apart from the huge sunshade, its main mirror has a diameter of 6.5 meters, far exceeding the diameter of any rocket currently in use. Since the mirror cannot be "glued" to one side of the rocket, clever NASA engineers decided to divide the mirror into 18 smaller hexagons, so that it can be stuffed into the rocket along with the folded "sunshade" and the rest of the telescope.

If everything goes smoothly, a few days after the James Weber telescope is launched, it will fly towards the observation point, deploy the mirror and sunshade in place, and then begin the observation mission.

And its observation results will be extremely astonishing. One of the main observation targets of this telescope will be the early universe, which was just a few hundred million years old. The first batch of stars and planets that appeared once emitted dazzling light in the visible light band. But over the past 13 billion years, the universe has gradually expanded, causing the wavelengths of these rays to become longer and longer, eventually leaving visible light and falling into the infrared band, which falls precisely within the ideal observation range of the James Weber telescope.

Since the first batch of stars and galaxies formed did not leave any images, this will be the first time we have observed this important period in the history of the universe.

The James Weber Telescope will study all "cold" objects in the universe, including protoplanetary disks around newborn stars, molecular cloud, comets, Kuiper belts, and so on.

The telescope will also use a special device to block light from some distant stars, thereby capturing any celestial bodies passing in front of these stars, such as exoplanets. These planets appear very bright in the infrared band, and through the light they emit, we can analyze the chemicals and elements in the planet's atmosphere, perhaps discovering signs of life.

In short, from searching for extraterrestrial life to uncovering the truth of the dawn of the universe, the James Weber Telescope will surely live up to our years of waiting.