We do not (yet) have direct evidence that life exists on other planets, their satellites, or in interstellar space. And yet, there are compelling and very compelling reasons to believe that we will eventually find such life, perhaps even in our solar system. Here are seven reasons why scientists believe that life certainly exists somewhere and is just waiting to meet us. Maybe it won't be green-skinned ladies in flying saucers, but it will still be aliens.
1. Extremophiles on Earth
One of the main questions is whether life can exist and develop in worlds radically different from the earthly one. It seems that the answer to this question is in the affirmative, if you think about the fact that even on our planet there are extremophiles, or organisms that can survive in extreme conditions of heat, cold, exposure to toxic (to us) chemicals, and even in a vacuum. We have found living creatures that live without oxygen at the very edge of hot volcanic vents on the ocean floor. We have found life in brackish ponds high in the Andes mountains, as well as in subglacial lakes in the Arctic. There are even tiny organisms called Tardigrades that can survive in the vacuum of space. So, we have direct evidence that life can exist quite successfully in a hostile environment on Earth. In other words, we know that life can persist under the conditions that we observe on other planets and their satellites. We just haven't found it yet.
2. Evidence of the presence of initial substances and prototypes of life on other planets and satellites
Life on Earth likely began from chemical reactions that eventually formed cell membranes and proto-DNA. But these primary chemical reactions may have begun in the atmosphere and ocean with complex organic compounds such as nucleic acids, proteins, carbohydrates and lipids. There is evidence that such “precursors of life” already exist on other worlds. They exist in the atmosphere of Titan, and astronomers have noticed them in the rich environment of the Orion Nebula. Again, this doesn't mean we've found life. However, we have found ingredients that many scientists believe contributed to the development of life on Earth. If such ingredients are common throughout the universe, then it is quite possible that life appeared in other places, not just on our home planet.
3. A rapidly increasing number of Earth-like planets
Over the past decade, celestial body hunters have discovered hundreds of extrasolar planets, many of which, like Jupiter, are gas giants. However, new planet-hunting techniques have allowed them to find smaller, rocky worlds like Earth. Some of them are even in orbit around their stars in the so-called “habitable zone,” that is, at a distance where they experience temperatures close to Earth. And given the huge number of planets located outside the solar system, it is likely that some form of life exists on one of them.
4. The enormous diversity and persistence of life on Earth
Life on Earth developed under extremely difficult conditions. Sometimes she managed to survive powerful volcanic eruptions, meteorite impacts, ice ages, droughts, ocean acidification and radical changes in the atmosphere. We are also seeing an incredible diversity of life on our planet in a fairly short period of time - in geological terms. Life is also a pretty persistent thing. Why shouldn't it originate and take root on one of Saturn's satellites or in another star system?
5. Mysteries Surrounding the Origin of Life on Earth
While we have theories about the origins of life on Earth that involve the complex carbon molecules I mentioned earlier, it is ultimately a mystery how such chemicals came together to form the fragile membranes that eventually became cells. And the more we learn about the unfavorable environment that existed on Earth when life arose and developed - a methane-filled atmosphere, boiling lava on the surface - the more mysterious the mystery of the origin of life becomes. One general theory is that simple single-celled life actually began somewhere else, perhaps on Mars, and was brought to Earth by meteorites. This is the theory of pansermy, and it is based on the hypothesis that life on Earth arose due to life on other planets.
6. Oceans and lakes are widespread, at least in our solar system.
Life on Earth originated in the ocean, and it follows that it could have emerged from water on other worlds. There is compelling evidence that water once flowed freely and abundantly on Mars, and Saturn's moon Titan has methane seas and rivers flowing across its surface. It is believed that Jupiter's moon Europa is one continuous ocean, warmed by the crust of this moon and completely covered with a thick protective layer of ice. Life could once have existed in any of these worlds, and perhaps it still does.
7. Evolutionary theory
People often use the Fermi Paradox as evidence that we will never find intelligent life in our universe. On the other side is evolutionary theory, which postulates that life adapts to its environment. Darwin and his contemporaries hardly thought about life on planets outside the solar system when they created their theory of evolution, but they also argued that where life could take root, it would certainly do so. And if you think that our environment is not only planets, but also other star systems, and interstellar space, then you can make an original assumption within the framework of the interpretation of evolutionary theory - that life will adapt to outer space too. One day we may encounter creatures that have evolved in ways unimaginable to us. Or we ourselves can someday become such creatures.
A significant part of humanity really wants to hope that we are not the only intelligent beings in the Universe and that our brothers in mind live in some distant galaxy. Such enthusiasts are not stopped either by the warnings of skeptics who warn that extraterrestrial intelligence may not be entirely peaceful, or by the statements of scientists that there are no conditions for the emergence of any life in the observable Universe. Activists continue to build theories of life on other planets 
, which ultimately prove to be of varying degrees of plausibility and are capable of surprising even specialists in a good way.
Where to look for life
The question of the possibility of the existence of life on other planets has been studied for a long time and carefully, not only by outright dreamers, but also by serious researchers. In this regard, the question arose of formulating the criteria that determine the possibility of the emergence and development of life. On this occasion, a lively and long-term discussion has developed around the hypothesis of a unique Earth. It was created during a discussion of the possibility of life appearing on other planets in the Universe. Proponents of the uniqueness of earthly life suggested that life could arise and develop into complex forms only in an environment that was the result of a unique set of circumstances.
Factors such as the mass and gravitational attraction of the planet, its proximity to the nearest star (that is, temperature and radiation conditions), the presence of an atmosphere and its chemical composition, and much, much more, had to coincide. Therefore, supposedly, the probability that all these conditions will coincide again is negligible, so that the Earth and the life that arose on it are unique and unrepeatable. But this hypothesis is currently actively criticized by scientists who believe that life can appear and create highly organized structures not only on terrestrial-type planets and with “terrestrial” conditions. It will simply be life in slightly different forms and with other basic functioning mechanisms - but it will be life that is also capable of evolving into some intelligent species. In addition, the Universe is truly huge, there is an incredible number of galaxies in it, and it would be enormous arrogance and ignorance to believe that the same situation that led to the emergence of life on Earth could never be repeated anywhere.
The most popular candidates did not live up to expectations
Almost from the very beginning of human interest in space and celestial bodies, the greatest attention was paid to the planets of the solar system that are closest in their characteristics to Earth - Mars and Venus. It is no coincidence that, thanks to works of science fiction, the word “Martian” has become largely synonymous with the concepts of “alien” and “alien.” So, Mars currently cannot be a habitat for complex life forms similar to those on Earth, although in its main characteristics it is close to our planet. However, the atmosphere here is so weak that it is practically non-existent, therefore, there are no conditions for breathing. In addition, due to the low atmospheric pressure, which is hundreds of times less than what is observed on Earth, the existence of liquid water on Mars is impossible.
Thus, there is no nutrient medium in which even the simplest bacterial forms of life could arise. There is an unconfirmed, but also not refuted, theory that bacteria could live on Mars in the past, but this does not affect the current situation. The same conclusion has to be made for Venus, albeit with slightly different accompanying data. Venus is too hot (surface temperature is about 500 degrees Celsius), high atmospheric pressure (about 100 times stronger than Earth's), high degree of saturation of the atmosphere with gases, which feeds a strong greenhouse effect 
. At the same time, the eternal principle “never say never” applies to Venus: there is no complex life on this planet and there never was, but the existence of microbes in the past (the Venusian atmosphere was once saturated with water) or in the present (under the surface of the planet) cannot be excluded.
Life may be closer than we think
Another likely candidate for the presence of life in the solar system is Saturn's moon Titan. At first glance, it is not the most obvious candidate for the role of the “cradle of life”: the surface temperature of Titan is approximately minus 180 degrees Celsius, there is no liquid water here, and the atmosphere does not contain oxygen. But there are original theories according to which there may be life on Titan in the form of bacteria that arose on the basis of the synthesis of hydrogen, which is contained in a dense atmosphere. Beneath Titan's icy crust, it has been established that there are entire seas of liquid methane and ethane, which have a much higher resistance to low temperatures than water. The structure of life could develop according to an alternative scenario and take elements such as hydrogen, methane and acetylene as chemical bases for the release of vital energy.
But at present, the most promising in terms of conditions for the emergence of elementary forms of life is another satellite of Saturn, Enceladus. It is also an ice-covered planet that reflects 90% of the sunlight that hits it and has a surface temperature of about minus 200 degrees Celsius. However, by 2014, thanks to data from the Cassini research probe, which repeatedly flew over Enceladus at an altitude of about 500 kilometers, very important assumptions were confirmed. Under the icy thickness of the planet, at least under its south pole, at a depth of about 10 kilometers, there is a real ocean of real liquid water, which in its composition is very close to earthly water. This ocean has an area of about 80 thousand square kilometers and an estimated depth of 20-30 kilometers. The chemical composition, as well as the fairly comfortable water temperature, makes the subsurface ocean of Enceladus a prime candidate for the presence of extraterrestrial microbial life forms. But to confirm this, it is necessary to organize a mission to this planet, which could collect water from the subglacial ocean and deliver it for analysis.
Alexander Babitsky
A planet on which life can originate must meet several specific criteria. To name a few: it must be at a distant distance from the star, the size of the planet must be large enough to have a molten core, and it must also have a certain composition of “spheres” - lithosphere, hydrosphere, atmosphere, etc.
Such exoplanets, located outside our solar system, can not only support life that originated on them, but they can also be considered as some kind of “oases of life” in the Universe if humanity suddenly has to leave its planet. Based on the state of development of science and technology today, it is obvious that we have no chance of reaching such planets. The distance to them is up to several thousand light years, and, based on modern technology, traveling just one light year would take us at least 80,000 years. But with the development of progress, the advent of space travel and space colonies, the time will probably come when it will be possible to be there in a very short time.
Technologies do not stand still; every year scientists find new means of searching for exoplanets, the number of which is constantly growing. Below we show you some of the most habitable planets outside the Solar System.
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10Kepler-283c
The planet is located in the constellation Cygnus. The star Kepler-283 is located 1,700 light years from Earth. Around its star (Kepler-283), the planet rotates in an orbit approximately 2 times smaller than the Earth around the Sun. But researchers believe that at least two planets (Kepler-283b and Kepler-283c) orbit the star. Kepler-283b is closest to the star and is too hot to support life.
But still, the outer planet Kepler-283c is located in a zone favorable for supporting life forms, known as the “habitable zone.” The radius of the planet is 1.8 times the radius of the Earth, and a year on it will be only 93 Earth days, which is how long it takes for this planet to complete a revolution around its star.
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9Kepler-438b
The exoplanet Kepler-438b is located in the constellation Lyra at a distance of about 470 light years from Earth. It orbits a red dwarf star, which is 2 times smaller than our Sun. The planet's diameter is 12% larger than Earth's and it receives 40% more heat. Due to its size and distance from the star, the average temperature here is about 60ºC. This is a little hot for humans, but quite acceptable for other life forms.
Kepler-438b completes its orbit every 35 days, which means that a year on this planet lasts 10 times less than on Earth.
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8Kepler-442b
Like Kepler-438b, Kepler-442b is located in the constellation Lyra, but in a different solar system that is further out in the Universe, about 1,100 light-years from Earth. Scientists are 97% confident that the planet Kepler-438b is in the habitable zone, and it makes a complete revolution around the red dwarf, whose mass is 60% of the mass of our Sun, every 112 days.
This planet is about a third larger than Earth, and it receives about two-thirds of our amount of sunlight, indicating that the average temperature there is about 0ºC. There is also a 60% chance that the planet is rocky, which is necessary for the evolution of life.
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7Gliese 667 CC
Planet GJ 667Cc, also known as Gliese 667 Cc, is located in the constellation Scorpius at a distance of about 22 light years from Earth. The planet is about 4.5 times larger than Earth and takes about 28 days to orbit. The star GJ 667C is a red dwarf star that is about a third the size of our Sun, and it is part of a three-star system.
This dwarf is also one of the closest stars to us, with only about 100 other stars being closer. In fact, it is so close that people on Earth using telescopes can easily see this star.
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6HD 40307g
HD 40307 is an orange dwarf star that is larger than red stars but smaller than yellow ones. It is 44 light years away from us and is located in the constellation Pictor. There are at least six planets orbiting this star. This star is slightly less powerful than our Sun, and the planet that is in the habitable zone is the sixth planet - HD 40307g.
HD 40307g is about seven times larger than Earth. A year on this planet lasts 197.8 Earth days, and it also rotates on its axis, which means that it has a day-night cycle, which is very important when it comes to living organisms.
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5K2-3d
The star K2-3, also known as EPIC 201367065, is located in the constellation Leo and is about 150 light years away from Earth. This may seem like a very large distance, but in fact, it is one of the 10 closest stars to us that have their own planets, so, from the point of view of the Universe, K2-3 is very close.
The star K2-3, which is a red dwarf and half the size of our Sun, is orbited by three planets - K2-3b, K2-3c and K2-3d. Planet K2-3d is the farthest from the star, and it is in the habitable zone of the star. This exoplanet is 1.5 times larger than Earth and orbits its star every 44 days.
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4Kepler-62e and Kepler-62f
More than 1,200 light-years away in the constellation Lyra, there are two planets - Kepler-62e and Kepler-62f - and they both orbit the same star. Both planets are candidates for the birth or adoption of life forms, but Kepler-62e is located closer to its red dwarf star. 62e is about 1.6 times the size of Earth and orbits its star in 122 days. Planet 62f is smaller, about 1.4 times the size of Earth, and orbits its star every 267 days.
The researchers believe that due to favorable conditions, it is likely that water is present on one or both exoplanets. They may also be completely covered in water, which is good news since it's possible that this is how Earth's history began. Billions of years ago, the Earth's surface may have been covered by 95 percent water, according to one recent study.
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3Kapteyn b
Orbiting the red dwarf star Kapteyn is the planet Kapteyn b. It is located relatively close to Earth, only 13 light years away. The year here lasts 48 days, and it is in the habitable zone of the star. What makes Kapteyn b such a promising candidate for possible life is that the exoplanet is much older than Earth, at 11.5 billion years old. This means it formed just 2.3 billion years after the Big Bang, making it 8 billion years older than Earth.
Since a large amount of time has passed, this increases the likelihood that life there currently exists or will appear at some point in time.
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2Kepler-186f
Kepler-186F is the first exoplanet discovered with the potential to support life. It was opened in 2010. It is sometimes called "Earth's cousin" because of its resemblance. Kepler-186F is located in the constellation Cygnus at a distance of about 490 light years from Earth. It is an ecoplanet in a system of five planets that orbit a fading red dwarf star.
The star is not as bright as our Sun, but this planet is 10% larger than Earth, and it is closer to its star than we are to the Sun. Due to its size and location in the habitable zone, scientists believe it is possible that there is water on the surface. They also believe that, like Earth, the exoplanet is made of iron, rock and ice.
After the planet was discovered, researchers looked for emissions that would indicate that extraterrestrial life existed there, but so far no evidence of life has been found.
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1Kepler 452b
Located approximately 1,400 light-years from Earth in the constellation Cygnus, this planet is called Earth's "bigger cousin" or "Earth 2.0." Planet Kepler 452b is 60% larger than Earth and is further away from its star, but receives about the same amount of energy as we receive from the Sun. According to geologists, the planet's atmosphere is likely thicker than Earth's and there are likely to be active volcanoes.
The planet's gravity is probably twice that of Earth. In 385 days, the planet revolves around its star, which is a yellow dwarf like our Sun. One of the most promising features of this exoplanet is its age - it was formed about 6 billion years ago, i.e. it is about 1.5 billion years older than Earth. This means that a fairly long period has passed during which life could have arisen on the planet. It is considered the most likely habitable planet.
In fact, after its discovery in July 2015, the SETI Institute (a special institution for the search for extraterrestrial intelligence) is trying to establish communication with the inhabitants of this planet, but has not yet received a single response message. Of course, after all, messages will reach our “twin” only after 1400 years, and if things go well, after another 1400 years we will be able to receive a response from this planet.
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Conclusion
This was an article TOP 10 planets that could theoretically support life. Thank you for your attention!
Yes, it's possible. The idea of a plurality of inhabited worlds was first expressed in the Middle Ages by Giordano Bruno. Obscurantists burned the scientist at the stake for this in Rome on February 17, 1600 in the Square of Flowers.
The materialistic understanding of the Universe affirms the origin and development of life on other planets, wherever conditions were favorable for this.
The conditions for the existence of life forms known to us are primarily: temperature not higher than + 100° C and not lower than - 100° C; the presence of carbon, which is the main component in the structure of living organisms; the presence of oxygen, the main participant in the vital, energy reactions of living organs; the presence of water and, finally, the absence of toxic gases in the planet’s atmosphere.
All these conditions can be met only in exceptional cases if we look for them in the Universe among countless stars and possible planetary systems. But it is precisely this innumerability of stars and their possible planets that greatly increases the likelihood of the existence of all these conditions in thousands, and perhaps millions of points in the Universe.
We are especially interested in our neighbors - the planets of our solar system, on which we can establish with sufficient accuracy the conditions existing on their surface.
Of all the planets in the solar system, the giant planets should immediately be excluded from the list of carriers of life: Saturn, Jupiter, Uranus and Neptune. They are bound by eternal ice and surrounded by poisonous atmospheres. On Pluto, the farthest from the sun, there is eternal night and unbearable cold; on Mercury, closest to the sun, there is no air. One side of it, always facing the sun, is hot, the other is immersed in eternal darkness and cosmic cold.
Three planets are most favorable for the origin of life: Earth, Venus and Mars.
Temperature conditions on all three planets do not go beyond those at which life is possible. Venus and Mars, like the Earth, have an atmosphere.
It is difficult to judge the composition of the atmosphere of Venus, since the planet is shrouded in a continuous cover of clouds. However, poisonous gases have been discovered in the upper layers of the atmosphere. The atmosphere of Venus is apparently extremely rich in carbon dioxide, which is fatal to animals, but serves as an excellent environment for the development of lower plants.
The existence of nascent life on Venus is possible, but cannot yet be proven. The situation is different with Earth's other neighbor, Mars.
What is Mars?
Mars is a planet with almost half the mass of Earth. It is removed from the Sun at a distance one and a half times greater than the Earth.
Mars rotates on its axis in 24 hours 37 minutes.
Its rotation axis is inclined to the orbital plane in approximately the same way as that of the Earth. Therefore, the same change of seasons occurs on Mars as we do.
It has been established that Mars is surrounded by an atmosphere in which no gases harmful to the development of life have been found.
Carbon dioxide is present on Mars in approximately the same quantities as on Earth. Oxygen there is assumed to be approximately one hundredth of the fraction that is available in the earth's atmosphere.
The climate of Mars is harsh and harsh and is accurately characterized in the story.
Mars is the same age as the Earth and has gone through all the same phases of development as the Earth.
During the period of its cooling and the formation of the first oceans, it was covered with continuous clouds, as Venus is now covered and as the Earth was covered during the Carboniferous period. During this “greenhouse” period of the planet’s development, the temperature on the surface of Mars did not depend, as it once did on Earth, on the Sun. Then the conditions on it were in all respects similar to those on earth, which, as is known, contributed to the emergence of life in the primordial oceans.
A similar process could take place on Mars.
During the greenhouse period, the first plants like the horsetails of the Carboniferous period, as well as other primitive forms of life, could have developed on the cloud-shrouded planet. Only in subsequent periods, when the cloud cover dissipated, Mars, having a smaller gravitational force than the Earth, lost particles of the atmosphere that was trying to break away from it and acquired conditions on its surface that were different from those on Earth.
However, life forms could adapt in the process of evolution to these new conditions. Along with the loss of atmosphere, Mars also lost water, which evaporated into the atmosphere and was carried away into outer space in the form of vapor.
Gradually, Mars turned into an arid, desert-covered planet.
Now on its surface there are dark spots that were once called seas. But if Mars had seas in ancient times, it lost them long ago. Not a single astronomer has observed glare that would be noticeable on the water surface.
The regions of Mars near the poles are alternately covered with a substance whose reflectivity resembles that of Earth's ice.
As the sun's rays heat up one or another polar region, this white cap (more accurate studies by G. A. Tikhov showed that it is green), like ice not covered with snow, decreases in volume, outlined by a dark stripe (apparently of moist soil ).
As it gets colder, the planet's ice cap begins to increase, and the dark limiting strip is no longer observed. This led to the conclusion that water vapor contained in the atmosphere of Mars (in small quantities) falls in the form of snow precipitation in the polar regions and covers the soil there with a layer of ice about ten centimeters thick.
As we warm, the ice melts and the resulting water either soaks into the soil or is somehow distributed around the planet.
This process occurs alternately at both poles of Mars. When ice melts near the south pole, it forms at the north pole and vice versa.
What is astrobotany?
This is a new Soviet science, created by one of our outstanding astronomers - corresponding member of the USSR Academy of Sciences Gavriil Andrianovich Tikhov.
Tikhov was the first to take photographs of Mars through color filters. In this way, he was able to accurately establish the color of parts of the planet at different times of the year.
Particularly interesting were the spots that were once called seas. These spots changed their color from a green-bluish tint in the spring to brown in the summer and brown tones in the winter. Tikhov drew a parallel between these changes and the change in color of the evergreen taiga in Siberia. Green in spring, bluish in the haze, the taiga turns brown in the summer and takes on a brown tint in winter. At the same time, the color of the vast expanses of Mars remained unchanged - reddish-brown, in all respects similar to the color of the earth's deserts.
The assumption that the spots on Mars that change color are zones of continuous vegetation required proof.
Attempts to detect chlorophyll on Mars using a spectral method, which ensures photosynthesis and the life of terrestrial plants, were unsuccessful.
Earth plants, as reported in the story, are also characterized by the fact that, photographed in infrared rays, they turn out white in the picture, as if covered with snow. If the areas of supposed vegetation on Mars turned out to be as white in infrared images, there would be no doubt about the existence of vegetation on Mars.
However, new photographs of Mars did not confirm bold assumptions.
But this did not bother G. A. Tikhov. He subjected a comparative study to the reflectivity of terrestrial plants in the South and North.
The results were amazing. Only plants that reflected without using these rays turned out white in photographs taken in infrared, thermal rays. In the north, plants (for example, cloudberries or mosses) did not reflect, but absorbed heat rays, which were by no means unnecessary for them. In infrared images, northern plants did not appear white, just as the areas of supposed vegetation on Mars did not appear white.
This research, supported by the polar and high-mountain expeditions of Tikhov’s students, allowed him to draw the witty conclusion that plants, adapting to living conditions, acquire the ability to absorb necessary rays and reflect unnecessary ones. In the South, where there is a lot of sun, plants do not need the thermal rays of the spectrum and > reflect them; in the North, poor in solar heat, plants cannot afford such luxury and strive to absorb all the rays of the solar spectrum. On Mars, where the climate is especially harsh and the sun is sparing, plants naturally strive to absorb as many rays as possible, and the failure of comparing Martian plants in this regard with southern plants of the Earth is understandable. They are more like arctic plants.
Having come to this conclusion, Tikhov also found a solution to the failures associated with attempts to detect chlorophyll on Mars.
Further study of this issue convinced Tikhov more and more of the complete analogy of the development of Martian plants with those on Earth. He discovered zones of vegetation on Mars in vast deserts, similar in reflectivity to those plants that grow in our Central Asian deserts.
Tikhov's reports about the mass flowering of some areas of Martian deserts in early spring are interesting. In color and character, these flowering zones on Mars are very reminiscent of the vast expanses of deserts in Central Asia, briefly covered with a continuous carpet of red poppies.
Recently, Tikhov has made interesting assumptions about the vegetation of Venus. Since there is more than enough heat on Venus, the plants of this planet, if there are any, should reflect the entire thermal part of the solar spectrum, that is, they should be red in color. The discovery of the Soviet astronomer Barabashev at the Pulkovo Observatory, who discovered yellow and orange rays through the clouds of Venus, allowed Tikhov to suggest that these rays are nothing more than a reflection of the cover of the red vegetation of Venus.
Not all scientists yet share the point of view of G. A. Tikhov. The task of the Astrobotany Sector of the Academy of Sciences of the Kazakh SSR is to find new, indisputable evidence of the existence of plant life on other planets and, above all, on Mars.
Are there canals on Mars?
These strange formations were first discovered by Schiaparelli during the great controversy in 1877. They appeared to him as regular straight lines, covering the planet in a network. He called them “canals,” being the first to express the cautious idea that these were artificial structures of the planet’s intelligent inhabitants.
Subsequent studies have cast doubt on the existence of the channels. The new observers did not see them.
An outstanding astronomer, Lowell devoted his life to the problem of the existence of life on Mars. By creating a special observatory in the Arizona desert, where the transparency of the air was favorable for observations, he confirmed Schiaparelli's discovery and developed his cautious idea. Lowell discovered and studied a huge number of channels. He divided them into main arteries (the most noticeable, double, as he claimed, canals), which went from the poles through the equator to the other hemisphere, and into auxiliary canals, coming from the main ones and crossing the zones in different directions in arcs in a large circle, that is, along the shortest path along the surface of the planet (Mars is a planet with a flat topography. There are no mountains or noticeable changes in the topography).
Lowell discovered two canal networks; one associated with the southern polar region of melting ice, and the other with the same northern region. These networks were visible alternately. When the northern ice melted, one could notice channels coming from the northern ice; when the southern ice melted, channels coming from the southern ice came into view.
All this made it possible for Lowell to declare the canals a grandiose irrigation network of the Martians, who built a gigantic system for using the water generated by the melting of the polar caps. Lowell calculated that the capacity of Mars's water pumping system would be 4,000 times greater than that of Niagara Falls.
Lowell saw confirmation of his thought in the fact that channels appear gradually, from the moment the ice begins to melt. They lengthen as if water moves through them. It has been established that the lengthening channel (or water in it) travels a distance of 4250 kilometers on the surface of Mars in 52 days, which is 3.4 kilometers per hour.
Lowell also established that at the points of intersection of the channels there are spots, which he called oases. He was ready to consider these oases as large centers of the inhabitants of Mars, their cities. However, Lowell’s idea did not find universal recognition. The very existence of the canals was called into question. When examining Mars through stronger telescopes, “channels” as continuous rectilinear formations were not detected. Only isolated clusters of dots were noticed, which the eye mentally tried to connect into straight lines.
The “channels” began to be attributed to optical illusion, to which only a few researchers succumbed.
However, an objective research method came to the rescue.
G. A. Tikhov, working at the Pulkovo Observatory, was the first in the world to photograph the canals of Mars. A photographic plate is not an eye; it would seem that it cannot make mistakes.
In recent years, photography of canals has been carried out on an increasingly wider scale.
Thus, during the 1924 confrontation, Tremiler photographed over a thousand Martian channels. Further photographs confirmed their existence.
The study of the coloring of the mysterious channels turned out to be extremely interesting. Their color is in every way similar to the changing color of the zones of continuous vegetation on Mars.
Calculation of the width of the canals (from one hundred to six hundred kilometers) led to the idea that the canals are not “canals - open excavations in the soil filled with water”; rather, they are strips of vegetation that appear as the water of melting ice flows through grandiose water pipes (with at a speed of 3.4 kilometers per hour. At this speed, after some time, a wave of seedlings occurs). These strips of vegetation (forests and fields) change color as the seasons change.
The assumption of the existence of water pipes buried in the soil with conclusions in the form of wells could reconcile observers who saw canals and observers who saw not straight lines, but only individual points located along straight lines. These points resemble oases of artificially irrigated vegetation in places where water pipes lead to the surface.
The assumption about the existence of buried pipes is all the more natural since, under the conditions of low atmospheric pressure on Mars, any open body of water would contribute to the rapid loss of water due to intense evaporation.
The debate about the essence of the channels is still ongoing, but it no longer calls into question their existence.
Deviating from a too bold assumption about the structures of intelligent inhabitants of Mars, some scientists are more likely to recognize the “channels” as cracks of volcanic origin, which, by the way, have not been found on any of the other planets in the solar system. This hypothesis also suffers from the fact that it cannot explain the movement of water along the canals without the existence of a powerful water-pressure system supplying polar waters through the equator to the opposite hemisphere.
Another point of view of astronomers is inclined to consider colored, geometrically regular stripes varying in length and color on Mars as traces of the vital activity of living beings who have reached the highest level of mental development, not inferior to the people of Earth.
What are the circumstances of the Tunguska disaster of 1908?
Based on the testimony of more than a thousand eyewitnesses - correspondents of the Irkutsk seismological station and the Irkutsk Observatory, it was established:
In the early morning of June 30, 1908, a fiery body (the nature of a fireball) flew across the sky, leaving behind a trail like a falling meteorite.
At seven o'clock in the morning local time, a dazzling ball appeared over the taiga near the Vanovara trading post, which seemed brighter than the sun. It turned into a pillar of fire, resting against the cloudless sky.
Nothing like this had ever been observed before when meteorites fell. There was no such picture when a giant meteorite fell in the Far East several years ago and scattered in the air.
After the light phenomena, a blow was heard, repeated many times, like a thunderclap repeated, turning into peals. The sound was heard at a distance of up to a thousand kilometers from the crash site. Following the sound, a hurricane of terrible force swept through, tearing off roofs from houses and knocking down fences at a distance of hundreds of kilometers.
Phenomena characteristic of earthquakes were felt in the houses. Oscillations of the earth's crust were noted by many seismological stations: in Irkutsk, Tashkent, Jena (Germany). Two tremors were recorded in Irkutsk (closer to the disaster site). The second was weaker and, according to the station director, was caused by an air wave that reached Irkutsk late.
The air wave was also recorded in London and circled the globe twice.
For three days after the disaster, luminous clouds were observed in the sky at an altitude of 86 kilometers in Europe and North Africa, making it possible to take photographs and read newspapers at night. Academician A. A. Polkanov, who was then in Siberia, a scientist who knew how to observe and accurately record what he saw, wrote in his diary: “The sky is covered with a dense layer of clouds, it is raining and at the same time it is unusually light. It is so light that in an open place you can quite easily read the small print of the newspaper. There shouldn’t be a moon, but the clouds should be illuminated with some kind of yellow-green, sometimes turning into pink, light.” If this mysterious night light noticed by Academician Polkanov were reflected sunlight, it would be white, not yellow-green and pink.
Twenty years later, Kulik’s Soviet expedition visited the site of the disaster. The results of the expedition's many years of searching are accurately conveyed by the astronomer in the story.
The assumption of a huge meteorite falling into the Tunguska taiga, although more common, does not explain:
a) Absence of any meteorite fragments.
b) Absence of a crater and craters.
c) The existence of a standing forest at the center of the disaster.
e) The presence of groundwater under pressure after the fall of a meteorite.
f) A fountain of water that bubbled up in the first days of the disaster.
g) The appearance of a dazzling ball, like the sun, at the moment of disaster.
h) Accidents with Evenks who visited the site of the disaster in the first days.
The external picture of the explosion that occurred in the Tunguska taiga completely coincides with the picture of an atomic explosion.
The assumption of such an explosion in the air over the taiga explains all the circumstances of the disaster as follows.
The forest in the center is standing on its roots, as an air wave fell on it from above, breaking off branches and tops.
Glowing clouds are the effect of the remnants of a radioactive substance flying upward on the air. Accidents in the taiga are the effect of radioactive particles falling into the soil. The sublimation, transformation into steam, of the entire body that flew into the earth’s atmosphere is natural at the temperature of an atomic explosion (20 million degrees Celsius) and, of course, no remains of it could be found.
The fountain of water that erupted immediately after the disaster was caused by the formation of cracks in the permafrost layer from the impact of the blast wave.
Is it possible for a radioactive meteorite to explode?
No, it's impossible. Meteorites contain all the substances that are found on Earth.
The content of, say, uranium in meteorites is about one two hundred billionth of a percent. For the possibility of a chain reaction of atomic decay, it would be necessary to have a uranium meteorite in an exceptionally pure form, and, in addition, in the form of the rare isotope Uranium-235, never found in its pure form. Besides everything, even if we assume such an incredible case that such a piece of “refined” Uranium-235 turned out to be in nature, then it could not exist, since Uranium-235 is prone to so-called “spontaneous” decay, involuntary explosions of some of its atoms . At the first such involuntary explosion, the supposed meteorite would explode immediately after its formation.
If we assume an atomic explosion, then there will inevitably be an assumption that a radioactive substance produced artificially exploded.
Where could a ship using radioactive fuel come from?
The closest star from us with a planetary system supposed to be around it is in the constellation Cygnus. This was discovered by our Pulkovo astronomer Deitch. The distance between us and her is nine light years. To cover such a distance, you need to fly at the speed of light for nine years!
It is, of course, impossible for an interplanetary spacecraft to achieve such speed. We can only talk about the degree of approximation to it. We know that elementary particles of matter - electrons - move at speeds of up to 300 thousand kilometers per second. If we assume that as a result of a long acceleration the ship would reach such a speed, we get that a round trip from the planet of the nearest star to us would have to take several decades. However, this is where Einstein's paradox comes to the rescue. For people flying at a speed close to the speed of light, time would move slower, much slower than for those who would observe their flight, after being in flight for decades, they would find that millennia had passed on Earth...
It is difficult to talk about the life expectancy of creatures unknown to us, but if we assume such a flight from Earth, then travelers, setting off on a flight, must devote their entire lives to it until they are very old. There is nothing to say about more distant stars and their planets.
Much more realistic would be the assumption of an attempt to fly from a closer planet and, above all, from Mars.
What does celestial navigation say?
Mars moves around the Sun in an ellipse, making one revolution every 687 Earth days (1.8808 Earth years).
The orbits of Earth and Mars converge at the point where Earth passes in the summer. Every two years, the Earth meets Mars in this place, but they are especially close to each other once every 15-17 years. Then the distance between the planets is reduced from 400 million to 55 million kilometers (the great opposition).
However, one cannot expect that it is enough for an interplanetary spacecraft to cover only this distance.
Both planets move in their orbits: Earth at a speed of 30 kilometers per second, Mars at 24 kilometers per second.
A jet ship, leaving a planet, inherits its speed along the orbit, directed perpendicular to the shortest path between the planets. In order for the ship to fly straight, it would be necessary to destroy this lateral speed along the orbit, wasting enormous energy uselessly on this. It is more profitable to fly along a curve, using speed along the orbit and adding to the ship only that speed that will allow it to break away from the planet.
To lift off from Mars, it will take 5.1 kilometers per second, and to lift off from Earth, 11.3 kilometers per second.
The prominent Soviet astronavigator Sternfeld made an accurate calculation of the routes and flight times of the interplanetary spacecraft in relation to the confrontations of 1907 and 1909. He received that the Martian ship, based on the condition of the greatest fuel economy, having departed from Mars at the most favorable time, should have reached the Earth either in 1907 or in 1909, but not in 1908! However, when flying from Venus, taking advantage of the opposition between Earth and Venus in 1908, the astronauts were supposed to arrive on Earth on June 30, 1908 (!).
The coincidence is absolutely exact, allowing us to make far-reaching assumptions.
Accordingly, before the great confrontation of 1909, the Martians who reached Earth in 1908 would have been in the most favorable conditions for returning to Mars.
Were there any signals from Mars?
The light signals from Mars noticed in 1909 are discussed in the article “Mars and Its Canals” in the collection “New Ideas in Astronomy,” published shortly after the great confrontation of 1909.
The once sensational talk about receiving radio signals from Mars in the early twenties during the confrontations between Earth and Mars is well known.
That was the time of the first flowering of radio technology created by the brilliant Popov, the appearance of the first publicly available radio receivers.
Y. Perelman, in the appendix to his book “Interplanetary Travel,” says that in 1920 and 1922, during the approach of Mars to the Earth, terrestrial radio receivers received signals that, by their nature, could not be sent by earthly stations (obviously, what was meant primarily was the length waves, very limited for the Earth's transmitting stations of that time). These signals were attributed to Mars.
Eager for sensations, Marconi and his engineers went on special expeditions to the Andes and the Atlantic Ocean to pick up Martian signals. Marconi tried to catch these signals at a wave of 300,000 meters.
Explosion on Mars
After the great confrontation between Earth and Mars in 1956, the director of the Pulkovo Observatory, corresponding member of the USSR Academy of Sciences A. A. Mikhailov, during his meeting with scientists at the Leningrad House of Scientists in Lesnoy, said that the Pulkovo Observatory recorded an explosion of enormous force on Mars... Judging Based on the fact that the consequences of this explosion were observed through telescopes, and knowing that there are no volcanoes on Mars, the observed explosion most likely should be attributed to a nuclear explosion. It is difficult to imagine a nuclear explosion on Mars that was not artificially caused. It may very well be that this explosion was deliberately caused for some constructive purposes. Thus, the observation of the Pulkovo Observatory can serve as one of the evidence in favor of the existence of intelligent life on Mars.
What is the history of the hypothesis?
For the first time, the hypothesis about the atomic explosion of an interplanetary spacecraft in the Tunguska taiga in 1908 was published in the story “The Explosion” by A. Kazantsev. (“Around the World”, No. 1, 1946)
On February 20, 1948, the author presented this hypothesis at a meeting of the All-Union Astronomical Society at the Moscow Planetarium.
The Moscow Planetarium popularized this hypothesis in the dramatization “The Mystery of the Tunguska Meteorite.”
At one time, major astronomers spoke out in defense of the right to put forward a hypothesis about the explosion of an interplanetary rocket over the Tunguska taiga, publishing a letter in No. 9 of the journal “Technology for Youth” in 1948. Among the scientists who signed it were: Corresponding Member of the USSR Academy of Sciences, Director of the Pulkovo Observatory Professor A. A. Mikhailov, Chairman of the Moscow Branch of the All-Union Astronomical Society Professor P. P. Parenago, Corresponding Member of the Academy of Pedagogical Sciences Professor B. A. Vorontsov-Velyaminov, Professor K-L. Baev, Professor M. E. Nabokov and others.
Subsequently, Professor A. A. Mikhailov proposed his own version of the Tunguska disaster, believing that the Tunguska meteorite was a comet, but this assumption did not have a wide resonance.
One of Kulik’s assistants, V.A. Sytin, believed that the Tunguska disaster was caused not by a meteorite fall, but by a colossal windfall. But this assumption does not explain the picture of the disaster and many of its details.
Experts on meteorites: Academician Fesenkov, Scientific Secretary of the Committee on Meteorites of the USSR Academy of Sciences Krinov, Professor Stanyukovich, Astapovich and others consistently adhered to the point of view that a meteorite weighing about a million tons fell into the Tunguska taiga, and resolutely rejected other points of view.
Aerodynamics research
The problem of the Tunguska meteorite has interested many. The famous aerodynamicist and aircraft designer from Antonov’s group, the author of good Soviet gliders, A. Yu. Monotskov, approached it strictly scientifically. Having processed the testimony of a huge number of eyewitnesses, correspondents of the Irkutsk Observatory, he tried to determine the speed at which the supposed “meteorite” was flying over various areas. He compiled a map, plotting the flight path and the time at which the “meteorite” was noticed by eyewitnesses at various points along the trajectory. The map compiled by Monotskov led to unexpected conclusions: the “meteorite” flew over the ground while braking... Monoidov calculated the speed with which the “meteorite” appeared above the explosion site in the Tunguska taiga, and received 0.7 kilometers per second (and not 30-60 kilometers per second, as was previously believed!). This speed approaches the flight speed of a modern jet aircraft and is an important argument in favor of the fact that the “Tunguska meteorite,” according to Monotskov, was an “aircraft” - an interplanetary spacecraft. If the meteorite fell with such an insignificant speed, then, based on the conclusions of the aerodynamicist, it turns out that in order to cause destruction in the taiga corresponding to the explosion of a million tons of explosives, it should have had a mass of not a million tons, as has been calculated so far astronomers, but a billion tons, having a kilometer across. This does not correspond to observations - the flying meteorite did not darken the sky. Obviously, the energy of destruction in the taiga was not thermal energy, into which the kinetic energy of the meteorite was converted when it hit the ground, but most likely was nuclear energy released during the atomic explosion of the fuel of the interplanetary spacecraft, without hitting the ground.
Scientific or non-scientific debate
Defenders of the hypothesis of a meteorite fall have repeatedly opposed the hypothesis of an explosion in the Tunguska taiga of an interplanetary spacecraft from another planet. They spoke in an extremely irritated tone and presented the following arguments.
1. It is impossible to deny the fall of a meteorite, because it is unscientific (why?).
2. The meteorite fell, but only drowned in the swamp.
3. A crater formed, but it was covered with swampy soil.
It was these arguments that Academician Fesenkov and Krinov made in the article “Meteorite or Martian ship?”, published in Literaturnaya Gazeta in August 1951. The effect of publishing the article was exactly the opposite of the wishes of its authors. The hypothesis about the Martian ship immediately became known to millions of readers. The newspaper began to receive many letters. Some of them quite rightly stated:
a) if a meteorite fell and drowned in a swamp, then where is it? Why was it not detected in the depths by magnetic instruments? Why didn’t its fragments scatter, which always happens when it falls?
b) if a crater was formed - it should be no less than Arizona in size, 1.5 kilometers in diameter, up to 180 meters deep - and this crater, according to meteorite scientists, was covered with swampy soil, then why are there no traces of a crater in the center of the disaster? formation, moreover, why did the peat layer and the permafrost layer remain intact, the latter should have melted? For what reasons could the “swampy soil covering the crater” freeze again, as if the ice age had returned to the earth?
As is known, meteorologists did not give answers to these questions, and they could not give them.
Sensational solution to the mystery of the Tunguska meteorite
Years passed, no one visited again the site of the alleged meteorite fall in the Tunguska taiga, but interest in this phenomenon, perhaps because of the cosmic hypotheses associated with it, did not weaken. And in 1957, meteorite experts were forced to speak in print again on this issue. Krinov in Komsomolskaya Pravda and Professor Stanyukovich in the magazine In Defense of Peace sensationally announced that the mystery of the Tunguska meteorite had finally been solved! There was a meteorite, but... it just sprayed into the air. Finally, meteorite scientists have abandoned the claim that a celestial body hit the Earth and the crater was “lost”! But no! Even this logic is alien.
Meteorites are only interested in the fact that part of the meteorite has been dispersed. To prove that the meteorite was sprayed into the air, it was reported that old jars with soil, once brought from the site of the Tunguska disaster, were found in the basements of the Academy of Sciences. Analysis of these forgotten cans revealed metal dust particles a fraction of a millimeter in size in the soil. Chemical analysis revealed the presence of iron, 7 percent nickel and about 0.7 percent cobalt, as well as magnetite balls measuring hundredths of a millimeter in size, a product of metal melting in air.
One can be glad that the Committee on Meteorites of the USSR Academy of Sciences, a quarter of a century later, made a discovery in the basements of the Academy and carried out a chemical analysis of old samples of taiga soil, but at the same time it must be admitted that the hasty announcement of solving the mysteries of the Tunguska catastrophe is somewhat premature.
In fact, if meteorologists are forced to agree that the meteorite never fell to the ground and for some reason turned to dust, then it is appropriate to ask the question: why did it turn to dust? What caused the explosion in the taiga if there was no impact of the celestial body on the ground and the energy of the meteorite movement did not turn into heat? And where did the colossal energy that felled hundreds of square kilometers of trees in the taiga come from in the event of a meteorite spraying? The meteorologists, who stubbornly clung to the meteorite version of the Tunguska disaster, have no answer to all these natural questions, and there cannot be one.
By the way, the presence of metal dust in soil samples from the Tunguska taiga does not at all prove that these are necessarily the remains of a meteorite. After all, the iron structure characteristic of meteorites has not been discovered. Most likely, we are dealing with the remains of the body (of an interplanetary rocket destroyed by an explosion. The chemical composition of these remains is the most suitable.
As we see, it is very difficult to dismiss the explanation of the Tunguska disaster as an atomic explosion. References to honorary academic titles with simultaneous neglect of a well-known fact - a monstrous explosion in the Tunguska taiga - do not in any way convince an inquisitive person. And this inquisitive person, of course, wants scientists to really explain the mystery of the Tunguska meteorite.
How can you solve the mystery of the Tunguska meteorite?
Sending a scientific expedition to the Tunguska taiga will be of undoubted interest. One has to wonder why the Academy of Sciences and its Committee on Meteorites have not yet risked sending such an expedition that could make a contribution, if not to meteorite science, then to our materialistic worldview. It’s very good that the expedition will still take place. Let's wish her good luck!
It is possible to resolve the question of whether an atomic explosion occurred in the Tunguska taiga. To do this, you will need to explore the area where the disaster occurred and examine it for radioactivity. For ordinary areas of the Earth there is a certain standard of radioactivity. With the help of special devices, Geiger counters, a very certain number of atomic decays can be detected in any place.
If powerful radioactive radiation (an atomic explosion) actually occurred in the area of the disaster at the time of the explosion, then the flow of neutrons (elementary particles emitted during the decay of atoms), passing through the wood of fallen trees and the soil, would inevitably cause some changes. So-called “tagged atoms” should have appeared, with heavier nuclei in which some of the passing neutrons were stuck. These labeled atoms are heavier isotopes (varieties) of elements commonly found on Earth. For example, ordinary nitrogen could turn into heavy carbon, which slowly decomposes on its own. Other heavy isotopes decay in the same way. This spontaneous destruction can be detected using the same atomic decay counters.
If it can be established that in the Tunguska taiga region the increased number of atom decays per second exceeds the norm, the nature of the Tunguska catastrophe will be clear. Moreover, it is also possible to establish the center of the catastrophe and, if it coincides with the dead forest, finally restore the entire picture of the death of the Martian ship.
A.P. Kazantsev, Guest from Space, GIGL, Moscow, 1958, 238 p.
NASA predicts that we will find life beyond our planet, and perhaps beyond our solar system, as early as this century. But where? What will this life be like? Would it be wise to make contact with aliens? The search for life will be difficult, but the search for answers to these questions could, in theory, be even longer. Here are ten points that are in one way or another related to the search for extraterrestrial life.
NASA believes extraterrestrial life will be discovered within 20 years
Matt Mountain, director of the Space Telescope Science Institute in Baltimore, has this to say:
“Imagine the moment when the world wakes up and the human race realizes that it is no longer alone in space and time. We have the power to make a discovery that will change the world forever.”
Using ground-based and space-based technologies, NASA scientists predict that we will find extraterrestrial life in the Milky Way galaxy within the next 20 years. Launched in 2009, the Kepler Space Telescope has helped scientists find thousands of exoplanets (planets outside the solar system). Kepler detects a planet when it passes in front of its star, causing a slight drop in the star's brightness.
Based on Kepler data, NASA scientists believe that 100 million planets in our galaxy alone could be home to extraterrestrial life. But only with the start of operation of the James Webb Space Telescope (launch scheduled for 2018) will we have the first opportunity to indirectly detect life on other planets. The Webb telescope will search for gases in planetary atmospheres that are generated by life. The ultimate goal is to find Earth 2.0, the twin of our own planet.
Extraterrestrial life may not be intelligent
The Webb telescope and its successors will look for biosignatures in the atmospheres of exoplanets, namely molecular water, oxygen and carbon dioxide. But even if biosignatures are discovered, they won't tell us whether life on an exoplanet is intelligent. Alien life may be single-celled organisms like amoebas, rather than complex creatures that can communicate with us.
We are also limited in our search for life by our prejudices and lack of imagination. We assume that there must be carbon-based life like us, and its intelligence must be similar to ours. Explaining this failure in creative thinking, Carolyn Porco of the Space Science Institute says: "Scientists don't start thinking about completely crazy and incredible things until some circumstances force them to."
Other scientists like Peter Ward believe that intelligent alien life will be short-lived. Ward admits that other species may suffer global warming, overpopulation, famine and eventual chaos that will destroy civilization. The same thing awaits us, he believes.
Currently, Mars is too cold to support liquid water and life. But NASA's Opportunity and Curiosity rovers, analyzing rocks on Mars, have shown that four billion years ago the planet had fresh water and mud in which life could thrive.
Another possible source of water and life is the third highest volcano on Mars, Arsia Mons. 210 million years ago, this volcano erupted under a huge glacier. The heat from the volcano caused the ice to melt, forming lakes in the glacier, like liquid bubbles in partially frozen ice cubes. These lakes may have existed long enough for microbial life to form.
It is possible that some of Earth's simplest organisms could survive on Mars today. Methanogens, for example, use hydrogen and carbon dioxide to produce methane and do not require oxygen, organic nutrients or light. They are ways to survive temperature changes like those on Mars. So when scientists discovered methane in the atmosphere of Mars in 2004, they assumed that methanogens were already living beneath the surface of the planet.
When we go to Mars, we may contaminate the planet's environment with microorganisms from Earth. This worries scientists because it could complicate the task of finding life forms on Mars.
NASA plans to launch a mission in the 2020s to Europa, one of Jupiter's moons. Among the mission's main goals is to determine whether the lunar surface is habitable and to identify locations where future spacecraft could land.
In addition to this, NASA plans to look for life (possibly intelligent) under Europa's thick layer of ice. In an interview with The Guardian, NASA lead scientist Dr Ellen Stofan said: “We know there is an ocean underneath this icy crust. Water foam emerges from cracks in the south polar region. There are orange stains all over the surface. What is this, after all?
The spacecraft that will go to Europa will make several flybys around the moon or remain in its orbit, possibly studying the plumes of foam in the southern region. This will allow scientists to collect samples of Europa's interior without the risky and expensive landing of a spacecraft. But any mission must ensure that the ship and its instruments are protected from the radioactive environment. NASA also wants us not to pollute Europe with terrestrial organisms.
Until now, scientists have been technologically limited in their search for life beyond our solar system. They could only look for exoplanets. But physicists from the University of Texas believe they have found a way to detect exomoons (moons orbiting exoplanets) through radio waves. This search method could greatly increase the number of potentially habitable bodies on which we can find extraterrestrial life.
Using knowledge of radio waves emitted during the interaction between Jupiter's magnetic field and its moon Io, these scientists were able to extrapolate formulas to search for similar emissions from exomoons. They also believe that Alfven waves (plasma ripples caused by the interaction of a planet's magnetic field and its moon) could also help detect exomoons.
In our solar system, moons like Europa and Enceladus have the potential to support life, depending on their distance from the Sun, their atmosphere, and the possible existence of water. But as our telescopes become more powerful and far-sighted, scientists hope to study similar moons in other systems.
There are currently two exoplanets with potential habitable exomoons: Gliese 876b (about 15 light-years from Earth) and Epsilon Eridani b (about 11 light-years from Earth). Both planets are gas giants, like most of the exoplanets we have discovered, but they are located in potentially habitable zones. Any exomoons on such planets could also have the potential to support life.
Until now, scientists have searched for extraterrestrial life by looking at exoplanets rich in oxygen, carbon dioxide or methane. But since the Webb telescope will be able to detect ozone-depleting chlorofluorocarbons, scientists propose to look for intelligent extraterrestrial life in such “industrial” pollution.
While we hope to discover an extraterrestrial civilization that is still alive, it is likely that we will find an extinct culture that destroyed itself. Scientists believe that the best way to find out whether a planet might have had a civilization is to look for long-lived pollutants (which remain in the atmosphere for tens of thousands of years) and short-lived pollutants (which disappear within ten years). If the Webb telescope detects only long-lived pollutants, there is a high chance that civilization has disappeared.
This method has its limitations. The Webb telescope can so far only detect pollutants on exoplanets orbiting white dwarfs (the remnants of a dead star the size of our Sun). But dead stars mean dead civilizations, so the search for actively polluting life may be delayed until our technology becomes more advanced.
To determine which planets could support intelligent life, scientists typically base their computer models on the planet's atmosphere in its potentially habitable zone. Recent research has shown that these models may also include the influence of large liquid oceans.
Let's take our own solar system as an example. Earth has a stable environment that supports life, but Mars - which lies on the outer edge of the potentially habitable zone - is a frozen planet. Temperatures on the surface of Mars can fluctuate by up to 100 degrees Celsius. There is also Venus, which is within the habitable zone and is unbearably hot. Neither planet is a good candidate for supporting intelligent life, although both may be inhabited by microorganisms that can survive extreme conditions.
Unlike Earth, neither Mars nor Venus has a liquid ocean. According to David Stevens from the University of East Anglia, “The oceans have enormous potential for climate control. They are useful because they allow surface temperatures to respond extremely slowly to seasonal changes in solar heating. And they help keep temperature changes across the planet within acceptable limits.”
Stevens is absolutely confident that we need to include possible oceans in models of planets with potential life, thereby expanding the range of the search.
Exoplanets with wobbling axes can support life where planets with a fixed axis like Earth cannot. This is because such "spinner worlds" have a different relationship with the planets around them.
The Earth and its planetary neighbors revolve around the Sun in the same plane. But spinning worlds and their neighboring planets rotate at angles, influencing each other's orbits so that the former can sometimes rotate with their pole facing the star.
Such worlds are more likely than fixed-axis planets to have liquid water on the surface. This is because the heat from the mother star will be evenly distributed on the surface of the unstable world, especially if it has its pole facing the star. The planet's ice caps will melt quickly, forming a global ocean, and where there is an ocean, there is potential life.
Most often, astronomers look for life on exoplanets that are within the habitable zone of their star. But some "eccentric" exoplanets remain in the habitable zone only part of the time. When outside the zone, they can melt or freeze violently.
Even under such conditions, these planets can support life. Scientists point out that some microscopic life forms on Earth can survive in extreme conditions - both on Earth and in space - bacteria, lichens and spores. This suggests that the star's habitable zone may extend much further than thought. Only we will have to come to terms with the fact that extraterrestrial life can not only flourish, as here on Earth, but also endure harsh conditions where, it seemed, no life could exist.
NASA is taking an aggressive approach to the search for extraterrestrial life in our universe. The Search for Extraterrestrial Intelligence (SETI) project is also becoming increasingly ambitious in its attempts to contact extraterrestrial civilizations. SETI wants to go beyond just searching and tracking extraterrestrial signals and start actively sending messages into space to determine our position relative to others.
But contact with intelligent alien life may pose dangers that we may not be able to handle. Stephen Hawking warned that a dominant civilization would likely use its power to conquer us. There is also an argument that NASA and SETI are overstepping ethical boundaries. Neuropsychologist Gabriel de la Torre asks:
“Can such a decision be made by the entire planet? What happens if someone receives our signal? Are we ready for this form of communication?
De la Torre believes that the general public currently lacks the knowledge and training needed to interact with intelligent aliens. The point of view of most people is also seriously influenced by religion.
The search for extraterrestrial life is not as easy as it seems
The technology we use to search for extraterrestrial life has improved greatly, but the search is still not nearly as easy as we would like. For example, biosignatures are generally considered evidence of life, past or present. But scientists have discovered lifeless planets with lifeless moons that have the same biosignatures in which we usually see signs of life. This means that our current methods of detecting life often fail.
In addition, the existence of life on other planets may be much more incredible than we thought. Red dwarf stars, which are smaller and cooler than our Sun, are the most common stars in our Universe.
But, according to the latest information, exoplanets in the habitable zones of red dwarfs may have an atmosphere destroyed by harsh weather conditions. These and many other problems significantly complicate the search for extraterrestrial life. But I really want to know if we are alone in the Universe.
