The first image of the James Webb telescope made one star into 18?
Is this a repeat of the Hubble mistakes?
The James Webb Telescope (JWST), the successor to Hubble, was developed by NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA), with a total of 25 years from tender to launch, and nearly $10 billion in research and development costs.
On December 25, 2021, the James Webb Telescope was successfully launched, using ESA's Ariane 5 rocket;
On January 30, 2022, the James Webb telescope successfully arrived in its intended orbit, about 1.6 million kilometers from Earth, at which point it began to work.
On February 12, 2022, NASA released the first images taken by the James Webb telescope.
There are two very strange problems with this batch of images:
The image is slightly blurry and does not match the powerful shooting ability of the James Webb telescope, most likely because the telescope is still in the debugging stage, and it is estimated that the follow-up will be better;
One of the 18 bright spots in an image taken by the James Webb telescope is actually a star numbered "HD 84406" that appears. In other words, the James Webb telescope snapped a star into 18 at once.
I believe that when you see here, you will definitely wonder, this has just launched the telescope, why is the first batch of images wrong?
In fact, it is not uncommon for the first images to have problems, and on April 24, 1990, the Predecessor hubble of the James Webb Telescope was successfully launched. In May 1990, after the first images of Hubble were sent back to the Earth Command Center, scientists were shocked, the images were very blurry, and there were virtual images.
So engineers spent weeks repeatedly examining Hubble and found that hubbell's main mirror edge was polished by 2200 nanometers during the manufacturing process, which made the reflected light at the main mirror edge unable to focus precisely, resulting in blurred images. In layman's terms, hubble has become a "nearsighted eye."
So, if you want to solve this problem, you have to give the Hubble telescope a pair of "glasses". It took nearly 3 years for NASA to get ready and have astronauts go to Hubble to repair it, which allowed hubbell to focus normally.
So the question is, is the James Webb telescope repeating the mistakes of hubble? If so, is there a way to fix it?
James Webb Telescope
The average distance of Hubble from Earth is about 600 kilometers, and if it is broken, astronauts can be arranged to repair it. However, the James Webb telescope is not good, it is about 1.6 million kilometers away from the Earth, and the average distance between the Moon and the Earth is 380,000 kilometers, which is equivalent to 4 times the distance between the Earth and the Moon. The farthest place astronauts have ever been to is the moon, and it was in the 60s and 70s of the last century. "1.6 million kilometers" for the current aerospace science and technology, it is difficult to arrange astronauts in the past, and it is even more difficult to come back.
Therefore, according to the current situation, if the James Webb telescope is broken, it can only be broken, there is no way to repair.
Fortunately, however, this time the problem is not bad, but related to the structure of the James Webb telescope.
The mirror system of the James Webb telescope consists of a primary mirror, a secondary mirror, and a three-mirror mirror. Among them, the structure of the main mirror is very complex, reaching a diameter of 6.5 meters, which is divided into 18 independent hexagonal lenses. So the biggest question for the james Webb telescope's optical system was: How do you bring the light from these 18 independent hexagonal mirrors together to the same point?
If this can be done, then the main mirror can really work. When photographing the star numbered "HD 84406", the light paths of the 18 hexagonal mirrors were scattered and did not converge. Therefore, the resulting image is 18 points of light, which actually represent 18 hexagonal mirrors to photograph the "HD 84406" star. So this happens because the James Webb telescope hasn't been tuned yet.
The research team will then adjust the 8 independent hexagonal mirrors according to these 18 light points, so that their light can converge to a point for imaging.
Not only that, but this time the researchers chose the "HD 84406" star because the brightness of the star is just right to help the James Webb telescope debug.
That said, shooting 18 points of light is not a bad thing for researchers, but a good thing, which is exactly what they need. On the contrary, if you don't shoot 18 points of light, a few, or only one, it will be a real disaster!