Two stars are approaching the Sun and threaten life on Earth. Communication with alien civilizations

There is hope that on the third exoplanet in the star Glise star 581 (Gleise 581) there is life. Of course, it is easy to foresee an objection: there is hope and to life closer - for example, on Mars. But that hope and this have completely different foundations. About Mars - a separate conversation. The grounds that life is on Glyze 581 s, exactly one thing: water, if it is there, can be in liquid form. As it turned out in the spring of this year, the planet Glize 581C makes one turnover in orbit for 13 days, and the distance from it to the parent star is about 14 times less than the distance from the Earth to the Sun. But since Glyze 581 is a red dwarf, that is, a relatively cold star, the average temperature on the surface of the planet should be low - from 0 ° to 40 ° C, or as it is customary to speak in astronomy, the planet is in the zone of life (habitable zone) stars .

Distant life

With all the abundance of our knowledge of life, something they are radically limited. For example, we do not know what other forms of life are possible, with the exception of the only known - earthly life. But earthly life is possible only on earthly conditions and is very sensitive to fluctuations in temperature, pressure, solar radiation levels. In the solar system, another planet with such or even similar conditions is impossible even theoretically. We need the planet somewhere "in other worlds".

"Red Dwarfs", such as glue, are ideal for finding such planets: they emit less light, and their zone of life is located on more close to them than to the sun, "says Young French Astrophysicik Xavier Bonfis (Xavier Bonfils), Working now in the center of Astronomical and Astrophysical Research of the University of Lisbon (Centro De Astronomia E Astrofisica
dA Universidade de Lisboa). The planets that are in this zone can easily be detected by analyzing the periodic changes in the spectra of stars (Radial-Velocity Method) - the most successful method of detection exoplanet today.

The opening of Glyze 581c was made with the help of 3, 6-meter La Silla Observatory telescope (La Silla) of the European Organization of Astronomical Studies in the Southern Hemisphere (ESO) and the most accurate spectrograph of the Harps spectrograph installed on it. Harps is able to catch speed changes with an accuracy of one meter per second (or 3.6 km / h) and today is the most successful tool for detecting exoplanets, especially with a small mass.

There is another indirect indication of the possibility of living on glyze 581c. It was discovered by the MOST project participants, launched four years ago. By virtue of the unusualness of this project, it should be said separately before talking about its results.

The MOST satellite (a reduction from Microvariability & Oscillas of Stars - which means "Mikrovariativity and Star oscillations") was removed into orbit from the Russian cosmodrome Plisetsk in 2005 and became the only Canadian Space Observatory. The satellite himself was created by the joint efforts of the Canadian Space Agency (Canadian Space Agency), producing the Aerospace equipment of Dynacon Enterprises Limited, and two universities - Toronto and British Columbia in Vancouver. However, access to the telescope installed on the satellite has not only scientists, but also the most common Canadians - astronomer students or just amateur astronomers.

For one and a half months of their continuous observations behind the star, its parameters practically did not change. Thus, this red dwarf is a stable source of light and heat for the surface of the planet, whose climate, therefore, is little prone to strong changes that would be destructive for the formation and development of life.

"In addition to everyone else, this means that the star is old and" calm, "the words of Professor of Physics and Astronomy of the University of British Columbia Jaymie Matthews (Jaymie Matthews) by the University Press Release. - Planets around it have a few billion years old. We know that life on Earth has developed within 3.5 billion years before a person appeared, so it can be hoped for the possibility of the existence of a difficult life on any of the planets around Glyze 581, if it has at least such age. "

It can be considered that the opening of the planet Glize 581 with again translates the question of the existence of life outside the Earth from the speculation to the plane of a specific scientific practice. One of the world's leading experts on Exoplanets Swiss Astrophysicik Michel Major - by the way, at most recently, the scientific mentor of the glorified now Xavier Bonfis - puts himself and more ambitious goal: to find no indirect signs, but direct evidence of extraterrestrial life. He believes that advanced researchers are less than two dozen years from the detection of signs of life on other planets - of course, provided that there is such a thing.

Right of hope

The question of whether there is a form of life, similar to earthly, long ago worried about the minds of people, regardless of their faith. Inspired by the humanistic liberty, thinkers of the Renaissance, and then European Enlightenment were convinced that heaven is full of life. The first book of Galileo Galilee "Star Bulletin" was instantly excavated precisely because his contemporaries hoped: With the help of a telescope, Galiley saw the inhabitants of the Moon. Burned in the last year of the XVI century Jordano Bruno (Giordano Bruno, 1548-1600) argued that life is on all heavenly bodies. Already almost our contemporary, the Russian philosopher-cosmist Vladimir Ivanovich Vernadsky (1863-1945) believed that life was the fundamental nature of matter, and until the oldest tried to find its signs in the deepest geological layers. However - alas. The end of the twentieth century brought deep disappointment. Life has more and more before scientists as a unique phenomenon and, apparently, very limited in time. When science fiction writers were depicted in their works a distant and inhuman reasonable life, everyone understood: this is their way to turn to earthly and human problems. We are in the universe of lonely, our presence is fleeting here and by chance.

However, ideas do not die. Some convictions would seem bizarrely, there are always eccentrics, which, despite all the evidence and all reasonable arguments continue to share them. Already, no one decade continues international efforts to search for extraterrestrial mind, the SETI project. Continue, although they remain still fruitless. We are systematically dying and reborn again hope to find traces of life - even if the past is on Mars.

Among the enthusiasts, a famous physicist theorist, one of the creators of quantum electrodynamics and quite effective technique Visualization of calculations in the theory of elementary particles called "Fainman Chart", Freeman Dyson. A few years ago, speaking at the Institute of Theoretical and Experimental Physics, where he was presented international Prize Pomeranchuk, Dyson outlined his theory of extraterrestrial life. If his theory is true, then it is necessary to look for life on distant planets or even asteroids of the solar system. Their remoteness from the Sun may be not so important: collecting the scattered rays of a distant shine, peculiar plants with spreader petals can hold the desired amount of water in the liquid state.

But one of the main principles of the search for extraterrestrial life was and remains the principle of "follow water" ("Follow the Water" Approach). The water was looking for and continue to search within the solar system: the Space Protection of NASA received in 1997 was the sensation on the availability of water on the satellite of Jupiter Europe. With no less inspiration was perceived last year the news on signs of water in liquid form under the southern, volcanic pole of Saturn Saturn Enselades.

Water may not be as rare in space, as the years ago, forty back. The expansion of cosmic bodies, where you can count on its presence, maybe in this sense to be considered encouraging. At the time of writing this article, there are already 236 exoplanets. True, most of them belong to the type of "hot jupiters", but the point is not at all that the planets of this type are more, just notice them easier. Glyze 581c is still unique with its similarity with the Earth.

Favorable proximity

Making assumptions about the emerging, young life on exoplanets, scientists inevitably compare it with life on ancient land. As a rule, young planets are a difficult place to survive, therefore molecules from which living organisms develop should be very resistant to harsh conditions.

With the help of the NASA space telescope, Spitzer (Spitzer) managed to find out that organic molecules - polycyclic aromatic hydrocarbons, presumably "bricks of life", even an explosion of a supernovae. For example, a significant amount of polycyclic aromatic hydrocarbons was found at the surface of the remains of supernova N132D, located at a distance of 163,000 light years in the neighboring galaxy of a large magtel cloud. These molecules were found inside comet, around the areas of the formation of stars and protoplanetic disks. Since all life on Earth is based on carbon, astronomers suggest that the carbon originally hit the land as part of these molecules - probably from comets that fell on the young planet then.

Scientists argue that nearly five billion years from the solar system, a large star exploded. If so, then polycyclic aromatic hydrocarbons who survived this explosion could become "seeds" of life on our planet. There is reason to expect that not only on ours. Only to recognize them, you need to know at least approximately what they can be similar.

Other worlds, if we consider them into a telescope, may not be at all like Earth. Plants on other planets, according to the evidence of an astrobologist from the Institute space studies The namedrd name (GISS) Nancy Jiang (Nancy Kiang) may be of any color, except for the blue. The color of vegetation depends on many parameters: different spectrum of the Suns, differences in the atmosphere, whose chemistry depends on the composition and parameters of the parent stars.

A radiation on the surface of the planet over the spectrum will be very different in the planets living in stars of different spectral types (from hot f2, through G2, K2 to very dull M5), and it will also depend on the concentration in the oxygen atmosphere, ozone, water vapor and carbon dioxide. No less important and that for assimilation sunlight Plants can use not only chlorophyll; Depending on the evolution, another compound can be taken to ensure the photosynthesis process, which will take away from the light of the star maximum available energy. Plants strive to absorb the most energetically saturated part of the spectrum, and the color of their leaves depends on the frequency of light, which the plant absorbs the least. Thus, chlorophyll absorbs basically blue and red, because the red light carries the greatest number of photons, and the blue has the greatest energy for each photon. The green light of the plant is basically reflected.

A group of scientists under the leadership of Victoria Meduse (Victoria Meadows) from the Virtual Planetary Laboratory (VPL) of California technological Institute (California Institute of Technology) has developed computer models that imitate planets close to the parameters to the ground, and their light spectra are in the form in which they can be seen in space telescopes. Planets on planets about more bright stars (eg, spectral class F) will reflect the red-yellow-orange part of the spectrum, that is, to have a "autumn appearance" - in the light of these stars, blue and ultraviolet rays are dominated.

Plants on the planet rotating around the red dwarf (the stars of the spectral class M, the mass of which range from 10-50% of the mass of the Sun), may look black! Such stars dim sun and emit mainly light in infrared, invisible human eye, range, and local plants will have to try to learn the entire spectrum of radiation falling on them. The black color, as you know, almost does not reflect the rays falling on it.

The least probably, according to Victoria Meduse, the fact that vegetation on other planets will be blue. Blue - the light of greater frequency, therefore, he carries more energy, so the plants will "try" as much as possible to use it. In addition to these colors, terrestrial planets can be purple if microorganisms are developing, synthesizing violet or purple pigments (retinol), as it happened on ancient land. The organisms of this color exist and now are the so-called halobacteria, in the membrane of which Retinol absorbs the green light and reflects the red and purple, the combination of which seems to us violet.

Considering the models of scientists, you can assume what "spectral signatures" and colors, testifying to the availability of life, can be sought on the planets: purple, green, yellow or black. However, do not forget that both computer models and the theoretical calculations were made on the basis of knowledge about the life of the earth, and still have to find out how valid they are for exoplanets.

After opening the Gliese 581 of the two exoplanets at the star, scientists began to record strange signals coming from this system. Because of their uncertainty, over time, their decoding has become an unofficial priority for all researchers of possible life on other planets. Recently, scientists from Pennsylvania University said that they could decipher the signal and determine its source.

It was originally believed that the signal comes from two planets rotating around the star in the zone suitable for the existence of liquid water. These planets even began to call "Planets of Zlatovlaski", it was assumed that their conditions ambient As much as possible to earth, in which life can exist. However, scientists say the opposite: planets are silent, and a strange signal comes from the star due to the processes occurring in its depths.

"For us, this is a very important result, because for the first time it refutes all previous contradictory assumptions and monitoring this intriguing dwarf star. Gliese 581 is significantly less than the mass by weight, but is located just 20 light years from the ground. But as another result, we found out that the number of planets rotating around the star is three, "Paul Robertson, the author of the research from the University of Pennsylvania.
"We also proved that some of these contradictory signals arrive not from the planets in the habitat, but from the star as a result of its activities. In addition, we found out that there is no clear confirmation that these three exoplans are in the habitat area where liquid water can exist, "Suffold Mahadevan, Astronomy Associate Professional and Astrophysics from Pennsylvania University.

In this image, the location of the three exoplanets is shown, the existence of which is confirmed by the star Gliese 581 in 2014. If it was previously assumed that three planets are rotated in the orbit of the star in the habitat, now it is exactly known that the planet is one (shown in blue), the other two were the signals of the star itself. Source: NASA / PENN STATE UNIVERSITY

Astronomers are searching for exoplanets, fixing changes in the spectrum of stars around which they rotate. This experiment is also called the Doppler method. Exoplanet and star interact with each other, as a result, small deviations occur in the speed of movement of the star in their orbit. However, this method is not entirely accurate. Such Doppler changes can manifest themselves as a result of various events in the magnetic field of stars, such as sunny (star) stains that can give completely wrong information about the presence of exoplanets in the orbit of the star. The research team has made its opening from the star Gliese 581 using advanced Harps spectrographs of the European Southern Observatory and Hires from the bracket observatory. Scientists were aimed at finding the most features that arise as a result of the effects of magnetic fields. Carefully choosing analysis methods, researchers have reinforced a signal coming from three exoplanets rotating around the star. But the signals that were previously attributed to two of the three planets disappeared and became indistinguishable from the overall noise background of the research. The disappearance of these signals with a detailed analysis only exoplanets, excluding the star, says that the signal just comes due to the life of the Gliese 581 itself.

"Such detailed research exoplanets instills faith in us that we are currently possessing sufficient knowledge and technical skills to study them in a similar way. And at the same time, we received a negative result: two promising exoplanets are not those as we thought. But I hope that it is rather plus than minus, because this is another confirmation of how well the analyzing equipment is well developed, "Paul Robertson.

Old Milk Stars M classroom, such as Gliese 581 in the constellation Scales, have about one third of the mass of our Sun and have so far been very attractive goals for searching for extraterrestrial life, since less active compared to conventional stars. One of the important findings made from research data tells us that the stars as a result of their livelihoods can emit signals in the same range as exoplans in the habitat, which significantly increases the risk of false detections of non-existent planets. One hope is avoided - the production of new high-precision devices.

For the first time, astronomers discovered the planet outside our solar system, which is potentially suitable for life, with temperatures like terrestrial, comparable to ground mass and size, and probably liquid water on the surface. What is nice, the potentially inhabitable world is just two dozen light years from us. Someday people can get there.

About the sensational find told international Group Of the 11 astronomers (from Switzerland, Portugal and France), which worked in Chile, on one of the telescopes of the European Southern Observatory (ESO). Scientists have found a planet near the star Gliese 581, Red Dwarf, located in the constellation scales.

The planet, which received the name GLIESE 581 C, has a mass of about 5 masses of the Earth. Its diameter is estimated at 1.5 diameters of our planet, so the force of gravity on its surface is approximately 1.6 g. Due to these parameters, astronomers also dubbed her "Super-Earth).

Scientists suggest that this planet is a rocky world, similar to the land of the appearance. how possible variant - It may be an ice planet. But in both cases there should be liquid water on its surface. Moreover, in the case of an icy world - it can be covered with the ocean completely.

Liquid water, as far as we understand, is a condition for the existence of life.

The star Gliese 581 removed only 20.5 light years from us (photo Digital Sky Survey).

Now about assumptions. Water should be present on the planet, they say the authors of the discovery, simply because this is our idea of \u200b\u200bthe mechanisms of formation of planets. But about the fact that it is liquid, there is a temperature on the surface calculated by astronomers: from 0 to 40 degrees Celsius.

Although GLIESE 581 has a lot of three times less solar, and shines 50 times weaker, the conditions on the superman are quite comfortable. After all, it is 14 times closer to his sun (compared with the removal of the earth from the Sun), and the year on that planet is 13 days.

Therefore, in the sky, her native sun looks 20 times more than our shine. True, there is still nothing definite about the rotation of the planet around the axis. If, because of the proximity of his sun, it is always facing it with one side - local life There will be problems.

In any case, this is the most attractive inhabitivity candidate of all 220 extra-air planets opened in last years. What is there, attractive - the only one for now. After all, other worlds or too hot, or too cold, or, finally, are simply gas giants, such as Jupiter.

For example, one of the extraced planets closest in mass to our native world - the OLGL-2005-BLG-390LB "pulls" just 5.5 lands. It is not surprising that after dozens of open gas giants, with the masses of several Jupiters, this "small" planet was dubbed "the sister of the Earth". But, alas, she was so removed from her star that a terrible cold reigns on her surface - minus 220 Celsius.

Such a superman may see people who managed to get to the Gliese 581 system (ESO illustration).

Xavier Delfosse from the University of Grenoble (Grenoble University), one of the team members who opened the Supermen, speaks of the Gliese 581 C: "On the Treasure map of the Universe, I would like to celebrate this planet with a big cross."

But the importance of discovery is not only in the first finding of a potentially inhabitable world.

The existence of the Super Gas suggests scientists that there may be a lot of worlds suitable for life in the near surroundings of the Sun.

Gliese 581 enters the list of 100 stars closest to the sun. And from this hundreds of 80% - the same red dwarfs. If they have rocky planets, comparable by mass with the earth and appealing around their suns in a zone suitable for living ... In general, stories about green men gradually acquire a scientific base.

According to the models, it is assumed that on Gliese 581 C there is an atmosphere, but from which it consists - while you can not say. Yes, and confidently determine - whether it is there at all - too. But one concern is connected with the potential atmosphere. If the atmosphere is too powerful, such as Venusian, the conditions on the surface of the planet will be too hot for the existence of liquid water.

Comparison of planetary systems Gliese 581 (left) and solar. And also - planets Gliese 581 C and Earth (illustration AP, ESO, NASA).

Interestingly, two years ago the same team of astronomers already found the planet near Gliese 581 - with a mass of 15 ground masses, that is, such a neptune. She moves around a star with a period of 5.4 days. At that time, astronomers had already seen hints to other planets at the same star.

Now a new set of measurements allowed to open the superman, and also showed clear signs of another planet, with 8 ground masses and a period of circulation of 84 days.

The planetary system surrounding the GLIESE 581 contains thus at least three planets.

Interestingly, red dwarfs are generally well suitable for searching with their low mass planets that are in the "dwelling" zone. After all, they have (red dwarfs) this zone is very close to the star. And in this case, the planet rotating there, even at low weight, will have a noticeable gravitational effect on the star.

And then it's time to mention the device that allowed astronomers to open the planets at Gliese 581. It is mounted on a 3.6-meter ESO telescope and called Harps (High Accuracy Radial Velocity for Planetary Search). This is a tool, as clearly out of the name, measuring the oscillations of the star ray speed caused by the appeal of the planets around it.

Gliese 581 radius speed fluctuations caused by the approach of three planets. The scale at the bottom is the orbital phases, vertically - speeds in meters per second (ESO illustration).

Star speed measurement accuracy Harps is colossal - it feels a difference in less than one meter per second. The oscillations of the radial speed, opened by the Astronomers of the Supermen, by the way, amounted to from 2 to 3 meters per second.

Every few years, humanity has new reasons for concern. The predictions of Nostradamus, the curse of Rasputin, the deathbed nonsense of Vanga and even forgotten by all the gods of Maya calendars: we just love the idea of \u200b\u200bthe apocalypse. Nevertheless, this time everything sounds somewhat more serious. Astronomers discovered a huge star in the sky, which may well destroy our entire planet. Moreover, it is assumed that the appearance of a similar star has already led to the disappearance of dinosaurs.

What it is

Glyze 710 is an orange dwarf of the spectral class K7. The mass of the star is very large and is more than half the mass of the sun, the diameter also exceeds half the diameter of our native star. Now imagine the giant flickering with hellish fire, carrying through the outer space right on the ground. That is what happens right now.

Where is she now

Astronomers of the Polish University named after Adam Mitskevich, Poznan, were engaged in the definition of accurate placement of stars killer. Glize 710 flies in 64 light years from the solar system. The fact that one light year is 9,461,000,000,000 km, to fly to us the star will have long.

On the hairs of death

A little earlier, the existence of glyze 710 was not very disturbed by scientists: the star was supposed to pass at a safe distance in one light year. However, today the astronomers received much more gloomy forecasts - the Glize 710 will fly only in 77 light days from the ground.

Oorta cloud

Collisions as such fear no need. Scientists are more concerned about this problem. The fact is that the star will pass through the so-called Oorta cloud (the area around our system, fully consisting of nuclei of the comet). Researchers suggest that the gravitational field of the stars will cause oscillations in the whole cloud. The deette cloud comets will be in the solar system and, most likely, will stay in the ground.

The star Gliese 710 will provoke a cometary rain from about 10 comet every year for 3-4 million years - Georgio Portus, Study Co-Author

Repetition passed

Some scientists suggest that the same passage of the star through the Oort cloud provoked the fall of the asteroid, which destroyed the dinosaurs about 65 million years ago. However, researchers are concerned about too large glyze sizes 710: if she really slip through the cloud comet, then the meteorites caused by it will not just destroy our species - they will reveal from the orbit all the planet.

Public as a hypothesis and himself strongly doubt it

Where is she now

On the hairs of death

Oorta cloud

The star Gliese 710 will provoke a cometary rain from about 10 comet every year for 3-4 million years - Georgio Portus, Study Co-Author