4.6 billion light-years away from the earth, the first clear photograph of the universe after the big bang

After more than 20 years of hard work, the most powerful space telescope in history costing 10 billion US dollars——

James Webb, just released the deepest photo of the universe to date.

This was the beginning of Webb – the first full-color image released, and the beginning of humanity’s peek at the Big Bang.

The galaxy cluster SMACS 0723, 4.6 billion light-years from Earth, is about the size of putting a grain of sand on your fingertip an arm’s length away.

According to NASA Administrator Bill Nelson, there are thousands of galaxies in this image alone, some of which have taken 13 billion years for their light to reach the mirror of the telescope.

You know, the Big Bang was only about 13.8 billion years ago. According to “Scientific American”, the light seen now is only a moment after the big bang.

Astronomers predict thatWebb will fill a mysterious void in our known history of the universe—the first 400 million years after the Big Bang—and will identify distant worlds where alien life may exist.

Some netizens lamented: Humans have never seen the depths of the universe so far and so clearly.

In addition, there are people who feel the insignificance of human beings and the vastness of the universe.

As the successor of the Hubble telescope, it is natural to compare them.

Some netizens thoughtfully made a moving picture and sighed: This 10 billion US dollars is not in vain.

How is this clarity achieved?

In fact, this galaxy cluster has been photographed by space telescopes before. It’s just that the Webb telescope achieved amazing clarity and revealed more detail in this area.

The accuracy achieved was far beyond the reach of the Hubble Space Telescope. If it is more similar, according to multiple media reports, it is a hundred times stronger.

The core contributor is the primary mirror six times larger than Hubble.

It consists of 18 hexagonal lenses, each weighing about 20 kg.

Its diameter is about 6.5 meters (Hubble is about 2.4 meters) and the area can reach 25.4 square meters.

A larger light-collecting area means that light from more distant galaxies is accepted.

In addition, the lens is made of high-purity metal beryllium, so that the surface can be almost absolutely smooth.

Second, the observation bands are different.

Webb focused on observing the universe in the infrared wavelengths, while Hubble mainly observed ultraviolet and visible light.

For initially formed stars and planets, they tend to hide behind visible-light-absorbing dust clouds. But infrared light from these regions can penetrate the shroud, revealing its interior information.

Therefore, infrared light waves are very important for observing the depths of the universe.

The light from the earliest stars and galaxies stretched out as it traveled through deep space, and by the time it reached Earth, the light had stretched into the infrared part of the spectrum.

In order to better receive infrared light waves, the Webb lenses are covered with gold.

Again, the track is different. Webb orbits the sun at the second Lagrangian point L2, which is 1.5 million kilometers from the earth; Hubble orbits the earth.

This point is chosen because it is subject to the gravitational force of the earth and the sun just right, so that the telescope and the earth can revolve around the sun synchronously; it can also always keep the sun, the earth, and the moon on the same side of the telescope, thereby shielding the interference of these heat sources.

In addition to “how to make it so clear”, netizens still have a few doubts.

For example, some curved celestial bodies appeared.

NASA officials also gave an explanation, which is simply the gravitational lensing effect.

Although this diagram shows a single sky, there are actually huge galaxies at different distances and distances. The gravitational pull of massive objects (galaxy clusters) to amplify or bend the faint light of smaller objects (galaxies, stars, or exoplanets).

There is also a hexagonal star in the photo, with a bar in the middle.

This is because Webb is a reflecting telescope. The hexagonal diffraction starburst is caused by the edge of the hexagonal lens of the primary mirror, and the horizontal one is from the secondary mirror bracket.

In other words, it can be said to be the unique logo of Webb’s shooting.

In addition, there is another point that the staff emphasized this time.

That is, this image was composited from images of different wavelengths in just 12.5 hours. If it were taken with the Hubble Space Telescope, it would probably take weeks, and there’s not that much detail.

Today’s performance, but behind it is a bitter history of “dove again and again”.

The 10 billion Webb telescope

In fact, from the day of birth, Webb’s goal is to step into the depths of the universe –

“Go back” to the early days of the Big Bang, looking for the light of the first stars and galaxies that formed in the universe after the Big Bang.

It is the largest and most powerful space telescope ever built.

It is an international cooperation project of NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). Thousands of engineers and hundreds of scientists do it together.

Interestingly, Webb’s history is known as “a generation of ace pigeons”.

As early as a year before Hubble’s launch (1990), scientists proposed to build a space telescope that could observe the mid-infrared spectral region.

Its name was finalized in 2002 in honor of James Webb, the second administrator of NASA and the principal initiator of the Apollo program.

It was originally planned to cost $500 million and was launched in 2007. However, due to various reasons, the project was severely overrun, and the launch time was delayed several times.

In 2004, its design drawings were basically completed after several revisions, and some parts began to be manufactured.

Its launch date was originally expected to be from 2007 to 2011, but due to the explosion of funding (the red line was initially set at $8 billion) and technical problems, it was postponed to 2014, and then to 2018 and 2019.

Finally in December last year, after more than ten years of waiting, “Ace Pigeon” completed the final test and took off.

Of course, it was originally expected to fly on the 22nd, but due to the weather, it “dove” for another 3 days.

(Me and my last stubbornness.jpg)

After taking 30 days, sailing 1.46 million kilometers and completing the “eyes open” (mirrors fully unfolded) on the road, “Ace Pigeon” Webb arrived at the “habitat” at the end of January this year: the second Lagrande Day point L2.

At this point, the guy who cost 10 billion US dollars and was dubbed by netizens as “alien peeping equipment” officially began to serve.

After months of lens alignment, calibration, and equipment tuning, Webb returned its first photos this summer, proving how “great” and “really good.”

Its mission, specifically, is to help scientists answer the following seven cosmic mysteries:

1. When and where did the first stars in the universe form?

2. What is the origin of supermassive black holes?

3. Is dark matter cold?

4. How do massive stars explode into supernovae?

5. Where does the water on a star like Earth come from?

6. Could the most promising exoplanets harbor life?

7. Does the expansion rate of the universe break current cosmological models?

According to the plan,Webb will run for 10 years, but NASA says it can actually last for 20 years.

It is worth mentioning that because Webb is too far from the earth, he cannot send people to repair it like Hubble, but can only send robots to replenish fuel.

ps. Hubble has been in operation for 32 years and has had multiple crashes, the most recent one was last year and is still in service.

At 10:30 tonight, there are 4 more photos to be released

Needless to say, this Webb image is the most distant and clearest image of the universe we humans have ever seen.

It integrates the crystallization of the collective efforts of many scientists for more than two decades.

Some netizens said, “The original picture is worth enjoying slowly”, “I just want to quietly say ‘so beautiful’”…

Others exclaimed:

In such a vast and profound universe, it would be a pity if there were no foreign civilizations.

Still, as some aerospace enthusiasts say, this photo is just an appetizer.

Just as the Hubble telescope helped us solve dark matter and many other cosmic mysteries, Webb will also take us once again into the hidden space, allowing us to observe it more deeply, discover some more incredible things, and constantly break Human knowledge of the universe.

Last but not least, remind everyone: NASA will announce the remaining 4 photos taken by Webb at 10:30 Beijing time tonight, including the Carina Nebula, the exoplanet WASP-96 b, the Southern Ring Nebula NGC3132 and Stephen Quintuple galaxies.

Interested friends don’t miss it.

Hashtags: telescope webb space telescope universe