Can the Webb telescope find extraterrestrial life soon? Scientists are confident

Scientists believe that although no extraterrestrial life has been found in the solar system, it is very likely to be found on exoplanets (planets outside the solar system, the same below), and they are full of expectations for the Webb telescope.

Chris Impey, professor of astronomy, and Daniel Arpey, professor of planetary science at the University of Arizona, believe that since the Webb telescope (hereinafter referred to as "Webb") can obtain spectral data of the atmospheres of exoplanets, it is possible to analyze the characteristics of these atmospheres and perhaps soon discover signs of extraterrestrial life.

Observing the atmospheres of exoplanets is just a sideline for the Webb telescope

The Webb telescope took 25 years to develop and cost $10 billion. It is the most expensive and advanced space telescope in history. The main mission of this telescope is very ambitious, which is to see the starting point of the Big Bang, that is, the universe 13.8 billion light years away.

Scientific observation and research have obtained the most important evidence of the Big Bang - the cosmic microwave background radiation, which is considered to be the embers left by the first light emitted by the Big Bang and the remnant of the most initial state of the Big Bang. The Webb telescope will investigate this light and restore the initial state of the Big Bang.

Therefore, the Webb telescope is equipped with highly sensitive infrared sensors, spectrometers, etc. The biggest difference from the Hubble telescope is that it can observe in the infrared band, which is longer than visible light. Since infrared rays can penetrate cosmic dust, and the diameter of the primary mirror is 2.7 times that of the Hubble telescope (hereinafter referred to as "Hubble"), and the light-collecting area is 6.5 times that of Hubble, the Webb's observation capability is 100 times that of Hubble.

How powerful is this ability? Some people compare it to being able to clearly identify a coin 40 kilometers away. Of course, this analogy is not very rigorous. If Weber is 100 times more powerful than Hubble, then does it mean that Hubble can only see a coin 400 meters away?

Since Webb was launched, it has been hit by six micrometeorites in space, the last of which was considered to be beyond the expected impact of the design, and people are worried that it will affect observations and images. However, the images released on July 12, Beijing time, are still amazing, and the difference is immediately apparent when compared with the Hubble Extreme Deep Field image.

It is said that with a grain of sand placed on the fingertip and the arm stretched out, Webb has photographed thousands of galaxies, the farthest of which is 13.5 billion light-years away from us; while Hubble's original photographs of the same location showed far fewer galaxies in the sky, and the clarity was completely different. (See the picture above)

This made many astronomers ecstatic, and more mysteries of the universe will be revealed. No wonder the US President couldn't wait for the original release time, and held a press conference one day in advance, with the president and vice president attending at the same time. The pictures released, which are much clearer than Hubble's, put everyone's heart at ease, and more than $10 billion was not thrown away in vain.

The images released are just a test run of Webb, and the real focused observations have not yet begun. Observing exoplanets is just a sideline, but this glimpse is really amazing, capturing the atmosphere of the planet, which indicates that by analyzing the atmosphere of the planet, it can be concluded whether there is life on that planet!

How do astronomers find exoplanets?

Since the beginning of the new era of space exploration in the last century, scientists have been hoping to find extraterrestrial life and even extraterrestrial civilizations. When humans could not see nearby planets clearly, they had many fantasies based on some clues they observed, such as Venusians and Martians.

In fact, as early as ancient times, people have imagined that there is life on the moon, the planet closest to us. In ancient China, there has been a legend that the beautiful Chang'e lives in the Guanghan Palace on the moon. The unmanned exploration of the moon and the manned lunar landing activities in the last century shattered the myth that has been passed down for thousands of years. Not only is there no one on the moon, there is no atmosphere, and there is no life at all.

So people turned their attention to Venus and Mars, the two planets closest to us. Through telescopes, we can vaguely see the dense atmosphere of Venus and the spider-web-like gullies on Mars. So people speculated that there were Venusians on Venus and Martians on Mars, and that the gullies on Mars were man-made projects built by Martians. Judging from the scale, the civilization there was much more powerful than humans, as they could build such a huge man-made project.

With subsequent planetary exploration activities, these fantasies were shattered one by one. Not only was no life found on Venus and Mars, but no evidence of life was found on any of the large and small planets, dwarf planets, and satellites in the entire solar system. However, scientists did not give up and are still tirelessly searching for life on planets such as Titan, Europa, Mars, etc., where they believe life may exist.

But one thing seems to have long been a consensus in the scientific community, that is, there is no possibility of advanced life outside the solar system. Even if there is life on those planets, it is extremely low-level fungal life. Therefore, scientists have long turned their attention to the outside of the solar system and started a large-scale search for exoplanets.

After decades of efforts, through the development of a series of increasingly advanced telescopes, more than 5,000 exoplanets have been discovered. These discoveries prove the fact that stars are generally accompanied by planets. But are there life or civilization on these planets? So far, there are no valuable clues.

But so far, the so-called "discovery" is not to actually "see" or see those planets clearly. To be frank, most of them are just "feeling" the existence of planets there. This is because human beings' current observation capabilities are too small compared to the vast universe. Even the most powerful telescopes cannot see the stars closest to us clearly. They can only see a bright spot, not to mention planets that are tens of thousands or even tens or millions of times smaller than stars.

The main method used to observe whether there are exoplanets around a star with a telescope is called the transit method, also known as the occultation method. When a planet is sandwiched between our line of sight to the star, the star will be occulted, that is, the luminosity will change a little bit, and it will appear periodically.

Through this light change phenomenon, and through some other auxiliary methods, scientists can roughly determine whether it is a planet, and calculate the mass of the planet, how far away it is from the star, and how long its revolution period is. Then, through some other methods such as the radial velocity method and the microlensing method, mainly through the Doppler effect and the law of gravity, the data of the planet is determined by the movement changes between the planet and the star. I will not explain it here.

Among the more than 5,000 planets, there are also very few that have been observed through direct imaging, but these so-called "imaging" is just a fuzzy light spot of a few pixels, which is generally captured through non-visible light such as infrared spectrum. These planets that have been directly observed now exceed 100, all of which are giant gas planets, most of which are dozens of times more massive than Jupiter.

In this way, what these discovered planets look like and whether there are signs of life on them is even more of a guess.

So how does Webb determine whether there is life on exoplanets?

The Webb telescope is the most powerful telescope ever built, and can clearly see a coin 40 kilometers away. But the universe is so vast that even the nearest star, Proxima Centauri, which is 4.3 light years away, would be much more than 40 kilometers away if it were shrunk to a coin. It would easily be equivalent to a coin of thousands or tens of thousands of kilometers.

Therefore, it is still a luxury to see a planet clearly. However, Webb has some skills of its own. Just after opening its eyes, it captured the atmospheric spectrum of a planet more than 1,000 light years away from us. In fact, before this, Webb's predecessor Hubble had already analyzed the atmospheres of many exoplanets and obtained a clear signal of the existence of water on a planet in 2013.

However, the signals observed by Hubble were still very vague and contained very little information. It was based on Hubble's observations that Weber further confirmed these evidences.

WASP-96b is a gas giant that has been discovered 1,150 light years away from us. Its mass is about half that of Jupiter, and its diameter is larger than Jupiter, 1.2 times that of Jupiter. It is located in the southern constellation Phoenix. This planet is very close to its own sun (star), only about 6.43 million kilometers away, only about one-ninth of Mercury's distance from the sun, and its revolution period is only about 3 and a half Earth days.

Webb observed WASP-96b for 6.4 hours, using the Near-Infrared Slitless Spectrometer (NRISS) to measure the planet's photometric variations and transmission spectra in the 0.6-2.8 micron band, revealing certain details previously hidden in the atmosphere, namely significant water features, signs of haze, and evidence of clouds, which were not certain or even thought to exist in previous observations.

In fact, Weber did not see clearly what the planet looked like, but through infrared observations, he obtained spectral data in the atmosphere. By analyzing these spectra, researchers can find out what components the planet's atmosphere is composed of and their respective abundance (content ratio).

The atmospheric components of planets with life and those without life have different characteristics. Certain elements can only be produced during life metabolism, and these life-related components will appear in the atmosphere. This is the atmosphere transformed by life and will show the characteristics of life, such as oxygen and methane in the atmosphere.

Plants and algae on Earth change the color of the atmosphere because chlorophyll and other pigments in photosynthesis capture certain wavelengths of light. Webb can sensitively capture these different color spectra through its sensitive infrared camera. If a planet is found to have a spectrum that indicates the presence of chlorophyll, it indicates typical evidence of the existence of life.

Of course, planets like WASP-96b are unlikely to have life. Webb is just practicing this time, which gives scientists a good sign. Among the more than 5,000 exoplanets discovered so far, Earth-like planets that are more likely to have life account for about 4%, or more than 200. Among them, there are dozens of so-called habitable planets, that is, planets that are not too far from the star and may have liquid water. These are the focus of Webb's future observations.

For example, TRAPPIST-1e, which is only 39 light-years away from us, is a planet similar to Earth. In the coming months, Webb will focus its lens on it. TRAPPIST-1 is a red dwarf star with a spectral type of M. Its planetary system is a very meaningful and special system. It actually has at least 7 Earth-like planets, 3 of which are in the so-called habitable zone!

Therefore, observing this planetary system will most likely reveal the existence of life! Therefore, scientists are full of hope. If extraterrestrial life is really discovered, it will be a huge breakthrough in human understanding of the universe and life, and scientific research will enter a new era. This is a great temptation for scientists who are constantly pursuing new discoveries.

Therefore, the Webb telescope has opened its eyes to the universe in the distant deep space, which is of epoch-making significance. The entire scientific community is paying attention to its new discoveries every day. What do you think about this? Welcome to discuss, thank you for reading.

The copyright of Space-Time Communication is original. Please do not infringe or plagiarize. Thank you for your understanding and cooperation.