Astronomer and popularizer of science Vladimir Surdin gave a lecture about whether there is life on Mars, the Moon, Venus, and when we will already meet aliens. Here are the main theses of the stories.
They searched for extraterrestrial life, starting from the nearest places. For example, in the 19th century, people were convinced that life could be on the moon - of course, on the other side, which we do not see. There are still a lot of myths that there are aliens who have their own base. In general, life there really is not excluded: only three days of flight is a place quite favorable for life. The moon had a definite life from 1969 to 1972 when humans explored its surface. By the way, they left their microflora there. But we do not know her fate.
There is ice on the moon, and the temperature is not very favorable, about -38 -40 degrees. If you fly there with a shovel and dig a dugout one and a half to two meters long, you will no longer suffer from daily temperature fluctuations. It must be remembered that life on our planet also prefers to originate underground. All biomass on the Earth's surface is less than below the surface to a depth of three kilometers.
In the early 1960s, it was expected that conditions on Venus were close to terrestrial, but it turned out that there is hell: the temperature is +400 and life is probably out of the question. Although there is one enthusiast, Moscow astrophysicist Leonid Vasilievich Ksanfomality, who points out some strange facts that may indicate the existence of life on Venus. But no one but him shares this idea.
Channels were discovered on Mars in the 19th century and until the middle of the 20th century. When the robots flew there and took pictures, there were no channels on them. We do not yet know where they went, but it is already clear that there is no civilization there. Although it is still not clear if there is any form of life there. Now there are robots on Mars that are not capable of doing biology, they are pure geologists. Thanks to the efforts of the European Space Agency and Roskosmos, biological work is to take place soon. My hope, like many who explore Mars, is to find the underground microflora. On the surface of the red planet, vertical caves of the karst type were found - the size of a stadium. It is clear that they lead to the collapsed underground volumes.
On the surface of Mars, life is excluded. There, the radiation level is off scale. Many people have probably watched the movie The Martian. So - it's all not true! For four years a person cannot walk on the surface of Mars, he will be irradiated to the state of a corpse. But under the surface of the planet, already at a depth of two to three meters, there is practically no radiation and there are quite good conditions: at least water will fill up (but in the form of ice). We dream of getting under the surface of Mars - in the absence of daily temperature fluctuations, in the presence of water and the absence of radiation, to look for life. But so far there is no robot that could climb caves, but there is an indirect indication of the presence of microflora on Mars. This is methane found in 2009 in its atmosphere. Methane does not last long in the atmosphere. It will decay from the action of solar ultraviolet radiation. So there is a source of this gas on Mars. On Earth, we have two main sources of methane - volcanic eruptions and microbial activity. There are no volcanoes on Mars, so only microbes remain.
Another hope to discover life outside the Earth is the satellites of the giant planets. They are about the size of the moon, some are smaller. They are covered with an ice crust outside, but under the ice there is a huge amount of water. There water is ideal for the development of life, but the only thing is that there is no sunlight. Although, in the depths of the ocean, life also flourishes without sunlight.
Biologists and astronomers are hoping to find an intelligent form of life. Because it is easier to detect. Try to find germs under the ice. And if this is an intelligent life, then it declares itself. For the first time this idea was clearly expressed in 1959 by two American physicists - then powerful radio transmitters and sensitive radio receivers appeared. Both were done to track the flight of interplanetary spacecraft. If this was done and huge radio antennas appeared, it suddenly turned out that if neighboring stars have the same technology, we can talk to them. It was completely unexpected, no one then thought about it, so a small note in the journal "Nature" blew people's brains. It turned out that we can already contact creatures similar to ourselves, living on neighboring stars.
Promotional video:
I must say that the gap in the distance between the planets of the solar system and the stars closest to us is colossal. In science fiction, it somehow looks natural, so we flew to Mars, flew to Alpha Centauri, it seems to be the same, but 100 thousand times farther from us to Mars than from us to Alpha Centauri - the closest star to us. A completely different scale of distances.
The main thing is to find an opportunity to exchange information. After all, we need to know where to send the signal: radio communication at interstellar distances is possible only with the help of directional antennas. Therefore, it was necessary to decide where to look and what to expect. It became obvious to everyone that it was necessary to find some common distance, so that every rational creature would understand that it was at this wavelength that radio communication should be established. Such a wave was found, a wave on which hydrogen radiates. This is an all-encompassing chemical element, it is the main one in the universe, everything is made of it, even our body to a large extent, stars are also almost of pure hydrogen. Hydrogen atoms emit just in the range that astronomers have already mastered. The wavelength is 21 centimeters, this is what we have in the television range, satellites broadcast on close waves. It `s that,what we already know how to do and hydrogen tells us that 21 centimeters is what you need to tune the radio to in order to try to receive a signal. But where to look - here it became a little more complicated.
The first to undertake such an experiment was the American astronomer Frank Drake. He realized that it was necessary to look for analogues of our solar system - in the vicinity of Alpha Centauri or Tau Ceti. When I was little, and my teachers did not know if these stars have planets. Drake first began to listen to broadcasts aimed at these stars. But in the end, the best thing that came out was probably Vysotsky's song about Tau Kit. Because the result of listening to the broadcast was zero.
In those years, this problem was called CETI - Communication with extraterrestrial intelligence. Then everyone hoped for communication, there was no doubt about the existence of civilization. In our country, the first impetus towards studying this problem was given by Joseph Samuilovich Shklovsky. He wrote a book in 1962 with absolutely no hope of any success. He just talked about the structure of space and the problem of communication with extraterrestrial civilizations. The book was called Universe, Life, Mind. It turned out to be just a bestseller. I recently edited another reissue of it and made sure it is very fresh.
This book was translated into English and there was a small scandal. Then the still young Karl Sagan undertook to translate it. But in English she came out under two names - Shklovsky and Sagan. He made himself a co-author. In general, even deservedly, because he added quite a lot, but did not agree with Shklovsky. It was not very pretty. One way or another, Sagan's great popularity began with the translation of Shklovsky's book.
The main thing is to find an opportunity to exchange information. After all, we need to know where to send the signal, radio communication at interstellar distances is possible only with the help of directional antennas. Therefore, it was necessary to decide where to look and what to expect. It became obvious to everyone that it was necessary to find some common distance, so that every rational creature would understand that it was at this wavelength that radio communication should be established. Such a wave was found, a wave on which hydrogen radiates. This is an all-encompassing chemical element, it is the main one in the universe, everything is made of it, even our body to a large extent, stars are also almost of pure hydrogen. Hydrogen atoms emit just in the range that astronomers have already mastered. The wavelength is 21 centimeters, this is what we have in the television range, satellites broadcast on close waves. It `s that,what we already know how to do and hydrogen tells us that 21 centimeters is what you need to tune the radio to in order to try to receive a signal. But where to look - here it became a little more complicated.
The first to undertake such an experiment was the American astronomer Frank Drake. He realized that it was necessary to look for analogues of our solar system - in the vicinity of Alpha Centauri or Tau Ceti. When I was little, and my teachers did not know if these stars have planets. Drake first began to listen to broadcasts aimed at these stars. But in the end, the best thing that came out was probably Vysotsky's song about Tau Kit. Because the result of listening to the broadcast was zero.
In those years, this problem was called CETI - Communication with extraterrestrial intelligence. Then everyone hoped for communication, there was no doubt about the existence of civilization. In our country, the first impetus towards studying this problem was given by Joseph Samuilovich Shklovsky. He wrote a book in 1962 with absolutely no hope of any success. He just talked about the structure of space and the problem of communication with extraterrestrial civilizations. The book was called Universe, Life, Mind. It turned out to be just a bestseller. I recently edited another reissue of it and made sure it is very fresh.
This book was translated into English and there was a small scandal. Then the still young Karl Sagan undertook to translate it. But in English she came out under two names - Shklovsky and Sagan. He made himself a co-author. In general, even deservedly, because he added quite a lot, but did not agree with Shklovsky. It was not very pretty. One way or another, Sagan's great popularity began with the translation of Shklovsky's book.
After the publication of Shklovsky's book, many enthusiasts of different directions appeared. Some took up the implementation of listening projects, and then sending signals into space. Others decided to look for traces of aliens on the ground. This is what we call ufology.
We are a little contemptuous of this direction, because it is a rather romantic hobby of not very literate people. There were aspects that interested historians and archaeologists. For example, the drawings in sugar on the walls of the caves, which reminded people of images of aliens. Further we have grandiose structures on earth, such as the pyramids of Cheops or the Baalbek veranda. The pyramid seems to be hand-built. But such structures as the Baalbek Veranda, where some bricks weigh 800 tons, raise questions. It seems impossible to do this, although there are works of theoretical archaeologists that explain in detail how it can be done. But until we see that modern people can repeat this work without the help of modern technology, there will always be some thought that these were aliens after all. This idea seems crazy to me: another civilization arrives and starts carrying stones. After all, we flew to the moon, returned from it, and no one there built any huge take-off sites.
Ufology is still alive and there are people who sincerely believe that aliens are already among us, kidnap us, study us, return us and everything like that. In the Soviet Union, the UFO craze began in 1977 and received a response from the official press and official science. Then over Petrozavodsk, over the Leningrad region, the so-called jellyfish was seen. Then it turned out that it was an unsuccessful rocket launch from the Plesetsk cosmodrome.
Great hope came in 1995, when scientists finally learned how to detect planets around other stars. It was not very easy, because there are many stars, and the planets, even if they are, shine very weakly. We never hoped to distinguish a small dot in this light, but still, methods were found. At first they were indirect. The star and planet revolve around a common center of mass. Obviously, the star must regularly move under the influence of the planet's gravity and the star's light will change its wavelength, and our spectroscope will show these regular oscillations. The light of a star that approaches us, then recedes from us, will cause fluctuations in spectral lines to the red and blue ends of the spectrum. In 1995, it worked.
The second method, which turned out to be more productive, is tracking how the planet passes against the background of its star - it eclipses it a little, by a fraction of a percent. You can see it. But it's best to do it from space. These space telescopes, which are not interfered with by the earth's atmosphere, do this very efficiently. To date, about four thousand planets have been discovered outside the solar system. It is fantastic. There are eight known planets in our solar system, and four thousand beyond it. Of course, we are interested in those that are like the earth. There are such, there are 40 of them. Planets similar to the earth and located in the life zone of their stars exist. We owe the Kepler telescope for the discovery of such planets.
But we need not only to know about these planets, but also to see and study them. We have already begun to do this: we have learned to see the chemical elements inherent in the elements of this or that planet. What exactly are we looking for? The spectrum of an exoplanet should contain biomarkers, that is, traces of those chemical elements that indicate either the existence of life or the conditions for it.
So, today we have not found life anywhere except the Earth. Moreover, the solar system. So it remains to try to find an intelligent life. To do this, it would be necessary to create giant radio telescopes in order to listen to the entire galaxy, all the stars. There are such projects, but there is no money for them - everything is as usual. But there are projects that listen to many channels at once. The SERENDIP project listens to almost 60 million radio channels. We have learned to make receiving equipment, but no one makes the corresponding radio antennas. This is expensive equipment.
There are a lot of stars, 200 billion. We have already learned how to select those that do not interest us. For example, if a star is massive, then it is unlikely that there is life on it. Because massive stars quickly end their lives and explode like supernovae. The age of our sun is also not particularly long (10 billion), it will exist for another five billion years, then life on Earth will end. But the massive ones are only five to six million years old. Better yet, embracing an entire galaxy with exploration. Andromeda is next to us, there are 400 billion stars. But too far away, our equipment is not yet capable of listening or transmitting signals.
Sometimes signals came, about which one could think that they were artificial. The famous "Wow" signal has been discussed since 1977. Literally this year, a work was published that just at the place of the signal a comet passed and in the cloud of gas that surrounds it, such a signal was generated. But no one gives up. There are signs by which they can be considered artificial. First, the signal must always change the transmission frequency. From space, we expect just such a hopping signal. Because our earth flies in space in one direction, their "earth" in the other, we constantly change the speed relative to each other and the Doppler effect should shift the frequency. This should be a sign that the signal is coming to us from a distant planet.
Have we listened to the whole cosmos? No. But there are certain sections that we have already been able to listen to. This is done by the old-timers-enthusiasts of the early 1960s - the private organization SETI Institute. They work on donations from people. At one time they were financed by NASA, but time passed, the signal was not received and the state stopped allocating funds. Projects continue to operate at the expense of the largest telescope. Interestingly, each of us can contribute to the development of this project simply by giving part of our computer time to analyze signals from space. All this is done very simply. On the net you find "SETI @ home", download a little program, it works and you don't notice it. The processor pumps the signals and if it finds something interesting, it informs you and sends it back to the SETI institute. A lot of such signals were found.
Text: Ksenia Buravova
