Perhaps we have found a second Earth?

A planet possibly suitable for life has been discovered near the star closest to the Sun; imagination already draws on it a dense atmosphere and oceans.

Found planet, named Proxima b, has an almost circular orbit, it is separated from the star by about 7.6 million kilometers (0.05 astronomical units, that is, the average distance of the Earth from the Sun). A year in this world lasts only 11 days, the mass of the planet is 1.3 times that of the earth, and the average surface temperature is close to zero degrees Celsius - this is only ten degrees lower than that of the Earth, and several tens of degrees higher than that of Mars .

By space standards, Proxima Centauri is very close - only 4.24 light years.

The parent star Proxima Centauri itself, which is characterized by strong ultraviolet and X-ray flares, can prevent the appearance of this paradise. This is described in a study published in the journal Nature.

Computer modeling has long suggested to astronomers that our neighbor has at least one planet, and in general, exoplanets are found around red dwarfs.

Opening Proxima b was accomplished by observing the Doppler shift in the spectrum of a star due to the gravitational influence of the planet. The work was carried out on two scientific instruments of the European Southern Observatory - HARPS (High Accuracy Radial velocity Planet Searcher) and UVES (Ultraviolet and Visual Echelle Spectrograph).

Despite the seemingly catastrophic proximity to the luminary, this world can be very good in terms of life support, because the stars are cold.

The surface temperature of Proxima Centauri is more than twice (almost three thousand kelvins), the mass is ten times, and the luminosity is four orders of magnitude less than that of the Sun.

And in order for the water on the surface of the planet not to freeze, it must be closer to its star much more than the Earth is to the Sun.

In the solar system, Venus, Earth and Mars are located in a similar zone, and the distance interval for the Proxima Centauri system is from 0.04 to 0.08 astronomical units. It would seem that everything speaks in favor of the emergence of life, but there is one unpleasant moment that can cross out all the advantages.

A distinctive feature of red dwarfs is their high activity. Flares in the X-ray range, periodically occurring on Proxima Centauri, are stronger than the most intense flare on the Sun by about 400 times. How such radiation will affect the emergence and maintenance of life is unknown. Perhaps such a superflare will be able to generate a chain of chemical reactions with the formation of molecules of organic substances, but, on the other hand, it is capable of “tearing off” the atmosphere from the planet. Possess planet Proxima b, like the Earth, by its own magnetic field, the destructive effect of radiation would be reduced, but its presence could not be detected remotely.

As a result of the most powerful flares on the Sun, up to a trillion megatons of TNT is released into the surrounding space in a few minutes. This is about a fifth of the energy radiated by the Sun in one second, and all the energy that a person will develop in a million years (assuming it is produced at modern rates). Superflares occur, as a rule, on larger stars of spectral types F8-G8 - massive analogues of the Sun (belonging to the class G2). These luminaries usually do not rotate rapidly around their axis and may be part of a close binary system. The power of superflares exceeds typical solar flares by tens of thousands of times, however, scientists do not exclude the possibility of such a cataclysm on the Sun.

Besides, planet Proxima b due to its proximity to the star, it is always turned to one side to it, that is, it is in a state of tidal capture, like the Moon in relation to the Earth. This means that one half of the planet is constantly hot, while the other is always cold. Simulations have shown that this will not be an insurmountable obstacle to the existence of life, provided there is a dense atmosphere. Constant convective flows will ensure heat exchange between the halves of the planet and a comfortable temperature can be established in the "border zone".

Most likely, such a large planet was formed in remote areas of the system and, over time, moved to its current position. Looking at the solar system, it can be argued that this celestial body contains a large amount of water.

Proxima Centauri is probably part of a triple star system, which also includes the double star Alpha Centauri, the stars in it are separated by only 23 astronomical units. The period of revolution of a red dwarf around two sun-like stars is more than 500 thousand years.

Flight to Alpha Centauri

Astrophysicist Philip Lubin (University of California at Santa Barbara) proposed to send a group of small automatic stations with . A system of lasers in Earth's orbit will accelerate them to near-light speed. A similar idea was proposed by Russian businessman Yuri Milner and British theoretical physicist Stephen Hawking.

The plans of both missions include only a flight through the system, because it will be impossible to slow down.

Difficulties in the implementation of the project are related to its technical component and price. To implement the Lyubin project, it will be necessary to deploy a constellation in Earth orbit that is a hundred times larger in mass than the ISS. It will take the miniature probe 15 years to reach Alpha Centauri and send back some photos, but the price of the issue is tens of trillions of dollars.

A modern spacecraft could do this much cheaper, but it would take 70,000 years.

Lubin's idea was supported by Congressman John Culberson, who urged NASA to begin work on an automatic mission to Alpha Centauri as early as 2017. The station, according to the plans of the Republican, should start in 2069 - the centenary of the landing of astronauts on the moon. The Milner-Hawking team also did not stand aside. At the event dedicated to the opening of Proxima b, it was announced that the Russian businessman planned to send probes to the mother star and the planet as early as 2030. The devices should reach the goal in 20 years. The first images of the nearest exoplanetary system on Earth will be seen in 2055.

The ideas of scientists and politicians were perceived with skepticism by most of their colleagues, and the remote study of Proxima b remains in the foreground. Problems when observing from Earth and from near space may arise due to the low luminosity and modest size of Proxima Centauri.

The closeness of the open world to the Sun makes it a prime target for future research. In addition, it is likely that there is a super-Earth in the orbit of Proxima Centauri, located outside the zone suitable for life. The period of its revolution around the star is from 100 to 400 days.

In the red dwarf Proxima Centauri, belonging to the star system Alpha Centauri and located at a distance of 4.25 light years from us, the planet Proxima Centauri b was discovered, and liquid water and other conditions for supporting life may exist on it. Of the 3,500 exoplanets that have been discovered outside the solar system since 1995, it is the closest to Earth.

Its mass is close to Earth's, while its year is ten times shorter. Despite being only a few million kilometers away from the star, it is potentially suitable for life to exist. The discovery was announced at a press conference by the European Southern Observatory in August 2016 in Germany.

The planet was discovered using the radial velocity method using the HARPS spectrograph of the European Southern Observatory. A large body, revolving around a star, seems to shake it with its gravity - the luminary either slightly accelerates towards the earthly observer, then, on the contrary, moves away from it. At the same time, in the radiation of the star reaching astronomers, a Doppler shift of the spectrum is observed, which is different for the moments of approach and removal. By determining the period of such oscillations of a star, astronomers find out the periodicity of rotation and the minimum mass of a body that affects it with its gravity.

For the planet Proxima Centauri b, the period of rotation around the star (year) is 11.2 days, and the minimum mass is 1.3 Earth. A year of 11.2 days means that the planet is closer to the center of the habitable zone. This is possible because Proxima Centauri is a red dwarf whose luminosity is 60 times less than that of the sun. Therefore, all planets with a year lasting from 4 to 15 Earth days are potentially habitable there.

Proxima is a red dwarf with a surface temperature of 3,000 Kelvin (half that of the Sun), so the planets in its habitable zone are very close to it. Proxima Centauri b lies only 7 million kilometers from the star. Because of this, the luminary's gravity has long achieved tidal capture - a state in which the rotation of the planet and the star is synchronized by gravitational interaction (as in the Moon-Earth pair).

This means that the planet is always facing the star with the same side, where eternal day reigns. In the other hemisphere, respectively, there is eternal night. An equally eternal sunrise and sunset dominates on the border of the illuminated and unilluminated zones of the planet. Earlier, a number of researchers expressed doubts about the possibility of the existence of complex life in such unusual conditions by our standards.

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In August 2016, the staff of the European Southern Observatory announced an amazing discovery. It turned out that around Proxima Centauri, the nearest star just 4.25 light years from us, with a period of 11.2 Earth days, an unusual exoplanet rotates - Proxima Centauri b. Its main feature is that the probability of having life on it is extremely high, although the conditions in which Proxima Centauri b is located are not at all the same as in the solar system. And if so, the story of this far-close planet is directly related to our beloved biology.

In general, we are serious people. The granite of science crunches on our teeth. We cover such harsh, such complex nooks and crannies of biological knowledge, which the lanterns of other popular science sites have not reached. But sometimes we just want to fool around. And to talk about science in a cheerful language, to show it from a different angle. Draw funny pictures, write light and funny text. That is why we have opened a new section - "12 biological news in pictures".

The intellectual partner of these illustrated stories is JSC RVC.

Information about the existence of Proxima Centauri b (shortly - just Proxima b) was leaked to the network on August 12, 2016. Literally two weeks after that, on August 24, employees of the European Southern Observatory confirmed the rumors about the discovery of a new planet. And several preprints of scientific articles appeared on the Internet at once, the authors of which discussed its habitability. Subsequently, a number of these articles were published in the journal Astronomy & Astrophysics .

First you need to say how the planet was discovered. Not all biologists are strong in physics, so it is all the more worth noting the method that made it possible to “see” the potential nearest habitable planet to us. It bears the name radial velocity method or Doppler method. The fact is that not only the star affects the planets belonging to it, but the planets also change the behavior of their star. The gravity of the planet slightly shifts the radial velocity of the star associated with it, as if rocking it. Changes of this kind are recorded by spectrographs, because the spectrum of the star changes.

In order for a planet to significantly influence the motion of its star, it must be quite large - have a mass no less than the earth's, but better at least several times more. So we can say for sure that Proxima b is “more chubby” than our space house. It is even known how much - 1.3 times.

What else do we know about this planet? It is known that it is 300 million years older than the Earth, which means that if life once arose there, it had more time to develop. Who knows, maybe the Proximovites are already developing vehicles capable of flying not much slower than the speed of light? Be that as it may, we cannot yet fly to test this: with our current space engines, it will take tens of thousands of years, and even then, provided that trillions of dollars are spent on the flight.

It is also known that the "host" of Proxima b, the star Proxima Centauri, is a red dwarf. The emission spectrum of stars of this type differs sharply from that of the sun. Red dwarfs put out much more ultraviolet light than yellow dwarfs like the Sun. In addition, they "spoil" their planets with X-rays. But in the case of Proxima b, this may not be so scary. The atmosphere there, apparently, is very dense, well delaying various harmful rays. Nevertheless, at the dawn of its time, the planet was hardly inhabited: then Proxima Centauri gave out a lot of ultraviolet and X-ray radiation, and only then “settled down”.

How to describe habitability?

The suitability of a planet for life is determined by several parameters:

• relatively small size and mass (about the same as that of the Earth);
• the temperature is at least in places above zero Celsius, but not much;
• the presence of liquid water;
• the absence of hard types of radiation that can damage DNA and other biological molecules.

This is not the whole list, but, perhaps, the main criteria are listed in it. In other words, potentially habitable planets should be similar to the Earth in many ways. And no wonder: this is the only planet known to us that is definitely inhabited.

More detailed discussions about the suitability of different planets for life can be seen in the article " wild wild space”, but as for our Earth, it is best to read the book by Mikhail Nikitin“ Origin of life. From Nebula to Cell» .

Hard ultraviolet radiation plays a cruel joke on life, because it splits water molecules into hydrogen and oxygen. Hydrogen also escapes easily from planets with moderate gravity. If so, scientists should have calculated how much water Proxima b could have lost during the time its red dwarf misbehaved. Let the density of the atmosphere of this exoplanet be approximately the same as that of the Earth. Then Proxima b could lose from 0.4 to 0.9 of the volume of the earth's oceans. It seems that this is a lot, but in fact it is quite small, given that our Earth has lost a quarter, or even more, of the water of its oceans in its history. And besides, a significant part of the losses can be restored due to the water contained in the planet's mantle. If so, most likely, there is enough water on Proxima b now. Moreover, this water is liquid: the planet is 20 times closer to its star than the Earth is to the Sun, and therefore, it is quite warm there.

In October 2016, there was even a hypothesis that the ocean on Proxima b could have a depth of up to 200 kilometers,. It is based on calculations of the diameter of the planet, depending on its composition, with a known mass (recall, this is 1.3 Earth). According to the authors of the scientific article, Proxima b probably has a compact core of silicates, covered with water on top. The mass of water is almost half of the mass of the entire planet.

The most interesting thing is that such an abundance of water does not help life, but rather reduces the likelihood of its presence on Proxima b. The fact is that such a thickness of H 2 O creates too much pressure at the bottom. Under such conditions, even hot water can turn into an exotic version of ice - so unusual that it does not exist on Earth. It will absorb up to 95% of the total mass of water on the planet. But ice - it is ice: its crust will not allow the ocean to communicate with the silicate core, which means that salt will have nowhere to come from. Well, distilled water is far from the best place for the emergence and maintenance of life. Let's remember school textbook blood cells that swell and even burst under the influence of water with a minimum salt content.

On the other hand, such a harsh model of Proxima b is extreme. The ocean there may not be that deep, it all depends on the physical parameters that are “driven” into the program. Their values ​​are yet to be confirmed experimentally.

As for the climate, the issue is complex. The planet is close to its star, which means that their mutual attraction can prevent Proxima b from rotating around its axis. As a result, the planet is probably always turned to its luminary with one side, very warm, and its other hemisphere is cold all the time. True, the difference in temperature between the "day" and "night" sides can be significantly smoothed out by a dense atmosphere. She, most likely, is on Proxima b.

By the way, calculations published already in 2017 lowered the likelihood that the planet does not really rotate around its axis. They showed that the orbit of Proxima b is quite elongated: its eccentricity is 0.25. And this means that at least at the extreme points of its orbit, the planet is not so strongly attracted by the star. Probably, on it, as on our Mercury, a day is equal to 2/3 of its own year and in this case lasts about one Earth week. All together, this means that the difference in climate at different points on the exoplanet is not so great, so the chances of finding life there increase.

One of the most outstanding astronomers of 2016 according to the magazine Nature Guillem Anglad-Escude even fantasized about what such a life would look like. He said in an interview with a Spanish popular science publication that "proximian" plants, if any, look unusual, because in the radiation of Proxima Centauri, the infrared part of the spectrum is the most invisible to our eyes. But this red dwarf almost does not give visible light of green shades, like that of the Sun. Thus, in order to survive under its rays as efficiently as possible, plants on Proxima b would do well to have a reddish tint, and not green at all.

Not only the local flora may look unusual. The fauna of red dwarfs will also be slightly unusual. If we assume that the biosphere there has reached large multicellular organisms, then among them there will be no analogues of polar bears, arctic foxes and other hares in winter coloring. She just doesn't make sense. 95 percent of the radiation from Proxima Centauri is infrared. Snow and ice in it are “black”, that is, they absorb light well and, unlike the Earth, quickly melt even with a short day. A stable snow cover in winter under such conditions is unlikely - just like animals in a "winter" camouflage coloration.

In general, whether there is life on Proxima b or not, it is not yet possible to say with absolute certainty. But the information currently available suggests that the patient is more likely alive than dead. And if he is alive, we can theoretically see a lot of interesting things on him.

Literature

1. Guillem Anglada-Escudé, Pedro J. Amado, John Barnes, Zaira M. Berdinas, R. Paul Butler, et. al. (2016). A terrestrial planet candidate in a temperate orbit around Proxima Centauri . Nature. 536 , 437-440;
2. Ortega I. (2016). European scientists highly appreciated the viability of Proxima b. "Life";
3. Martin Turbet, Jérémy Leconte, Franck Selsis, Emeline Bolmont, François Forget, et. al. (2016). The habitability of Proxima Centauri b. "Life";
4. Ortega I. (2016). Astronomer of the Year: Planet near nearest star covered in strange vegetation. "Life"..

With the help of telescopes of the European Southern Observatory (ESO), astronomers have managed to make another amazing discovery. This time they have found clear evidence of the existence of an exoplanet orbiting the closest star to Earth - Proxima Centauri. The world, called Proxima Centauri b (Proxima Centauri b), has long been sought by scientists all over the Earth. Now, thanks to his discovery, it has been established that the period of his revolution around his native star (year) is 11 Earth days, and the surface temperature of this exoplanet is suitable for the possibility of finding water in liquid form. By itself, this stone world is slightly larger than the Earth and, like the star, has become the closest to us of all such space objects. In addition, it is not just the closest exoplanet to Earth, it is also the closest world suitable for the existence of life.

Proxima Centauri is a red dwarf, and it is located at a distance of 4.25 light years from us. The star got its name for a reason - this is another confirmation of its proximity to the Earth, since proxima is translated from Latin as “nearest”. This star is located in the constellation Centaurus, and its luminosity is so faint that it is completely impossible to see with the naked eye, and besides, it is quite close to the much brighter pair of stars α Centauri AB.

During the first half of 2016, Proxima Centauri was regularly observed using the HARPS spectrograph installed on the 3.6-meter telescope in Chile, as well as simultaneously by other telescopes from around the world. The star was studied as part of the Pale Red Dot campaign (a pale red dot or red speck), during which scientists from the University of London studied the oscillations of a star caused by the presence of an unidentified exoplanet in its orbit. The name of this program is a direct reference to the famous image of the Earth from the far reaches of the solar system. Then Carl Sagan called this picture (blue speck). Since Proxima Centauri is a red dwarf, the name of the program has been adjusted.

Since this topic of exoplanet search has generated widespread public interest, scientists' progress in this work from mid-January to April 2016 was constantly publicly published on the program's own website and through social media. These reports were accompanied by numerous articles written by experts from all over the world.

“We received the first hints of the possibility of the existence of an exoplanet here, but our data then turned out to be inconclusive. Since then we have been working hard to improve our observations with the help of the European Observatory and other organizations. For example, the planning of this campaign took approximately two years,” Guillem Anglada-Escude, head of the research team.

Data from the Pale Red Dot campaign, combined with earlier observations from ESO's observatories and others, showed a clear signal of the exoplanet's presence. It has been very accurately established that from time to time Proxima Centauri approaches the Earth at a speed of 5 kilometers per hour, which is equal to the usual human speed, and then moves away at the same speed. This regular cycle of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting Doppler shifts indicated the presence of a planet here with a mass of at least 1.3 times the mass of the Earth at a distance of 7 million kilometers from Proxima Centauri, which is only 5 percent of the distance from Earth to the Sun. In general, such a detection has become technically possible only in the last 10 years. But, in fact, even signals with smaller amplitudes have been detected earlier. However, stars are not smooth balls of gas, and Proxima Centauri is a very active star. Therefore, accurately detecting Proxima Centauri b became possible only after obtaining a detailed description of how the star changes on time scales from minutes to decades, and monitoring its luminosity with light-measuring telescopes.

“We continued to check the data so that the received signal did not contradict what we found. This was done every day for another 60 days. After the first ten days, we had confidence, after 20 days we realized that our signal was in line with expectations, and after 30 days all the data categorically stated the discovery of the exoplanet Proxima Centauri b, so we began to prepare articles on this event.

Red dwarfs, such as Proxima Centauri, are active stars and have many tricks in their arsenal to be able to mimic the presence of an exoplanet in their orbits. To eliminate this error, the researchers monitored the change in the brightness of the star using the ASH2 telescope at the San Pedro de Atacami Observatory in Chile and the Las Cumbres Observatory telescope network. Information about radial velocities as the star's luminosity increased was excluded from the final analysis.

Despite the fact that Proxima Centauri b rotates much closer to its star than Mercury orbits the Sun, Proxima Centauri itself is much weaker than our star. As a result, the discovered exoplanet is located exactly in the region around the star, suitable for the existence of life as we know it, and the estimated temperature of its surface allows the presence of water in liquid form. Despite such a moderate orbit, the conditions of existence on its surface can be very strongly influenced by ultraviolet radiation and X-ray flares from the star, which are much more intense than the effects that the Sun has on Earth.

The actual possibility of this kind of planet supporting liquid water and having life like Earth is a matter of intense but mostly theoretical debate. The main arguments that speak against the presence of life are related to the proximity of Proxima Centauri. For example, on Proxima Centauri b, such conditions can be created under which it always faces the star on one side, which is why there is eternal night on one half and eternal day on the other. The planet's atmosphere could also slowly evaporate or have more complex chemistry than Earth's due to strong ultraviolet and X-ray radiation, especially during the star's first billion years of life. However, so far, no argument has been definitively proven, and it is unlikely that they will be eliminated without direct observational evidence and obtaining accurate characteristics of the planet's atmosphere.

Two separate papers were devoted to the habitability of Proxima Centauri b and its climate. It has been established that today the existence of liquid water on the planet cannot be ruled out, and in this case it can be present on the surface of the planet only in the sunniest regions, either in the hemisphere of the planet, always facing the star (synchronous rotation), or in the tropical zone (3: 2 resonant rotation). The rapid movement of Proxima Centauri b around the star, the strong radiation of Proxima Centauri and the history of the formation of the planet made the climate on it completely different from that on Earth, and it is unlikely that Proxima Centauri b has seasons at all.

One way or another, this discovery will be the beginning of large-scale further observations, both with current instruments and with the next generation of giant telescopes, such as the European Extremely Large Telescope (E-ELT). In the coming years, Proxima Centauri b will become a prime target for the search for life elsewhere in the universe. This is quite symbolic, since the Alpha Centauri system is also chosen as the target of humanity's first attempt to move to another star system. The Breakthrough Starshot project is a research and engineering project within the Breakthrough Initiatives program to develop a concept for a fleet of light sail spacecraft called the StarChip. This type of spacecraft would be able to travel to the Alpha Centauri star system, 4.37 light-years from Earth, at between 20 and 15 percent of the speed of light, which would take 20 to 30 years, respectively, and about 4 more years to notify the Earth of a successful arrival.

In conclusion, I would like to note that many accurate methods for searching for exoplanets are based on the analysis of its passage through the disk of a star and starlight through its atmosphere. There is currently no evidence that Proxima Centauri b passes through the disk of its parent star, and the chances of seeing this event are currently negligible. However, scientists hope that in the future the efficiency of observational instruments will increase.

If you weren't on Earth on Wednesday, you missed this: astronomers have found a planet as close to us as it can possibly be in the nearest star system, Alpha Centauri. A planet called Proxima Centauri b completes a circle around its star every 11.2 days. And yes, it is in the "potentially habitable zone", the Goldilocks zone, where liquid water can (for now) be on the surface. Its mass - 1.3 Earth - implies that the planet should (so far only should) be solid. No wonder we have already listed it as one of the greatest discoveries of the century.

But wait a minute. Astronomers have found other Earth-like planets in habitable zones in recent years. According to the Planetary Habitability Laboratory at the University of Puerto Rico, the existence of 15 potentially habitable "Earth-sized" exoplanets (in terms of mass or radius) has now been confirmed. And while yes, Proxima Centauri b has a mass that is oh so close to Earth, otherwise it might not be so earthy.

What really sets this planet apart from the competition and what caught my attention in the first place is its location. In the same way that the nearest supermarket to the house will become the most visited store for you, Proxima Centauri b warms the soul of scientists with its proximity and attractiveness. However, this attractiveness is still in question.

First, scientists so far only know the minimum mass of Proxima Centauri b - the smallest mass that it can have - and do not know its radius. That is, they do not know for sure whether it is solid or not.

“Remember we only have the minimum mass of this planet,” astronomer Elizabeth Tasker tweeted. “By that measure, I would be the twin of most life forms on Earth.”

In addition, the star harbors the planet with high-energy radiation, which means it dried up all the water a long time ago. If at least some hydration remains, it will be only in the most sunlit places. While "warm enough to have water" is an important fact, it cannot be equated with actual habitability.

Rory Barnes, an astronomer at the University of Washington, has developed a habitability index that evaluates potentially pleasant planets based on a large number of nuances. And his conclusions are disappointing. "I'm pessimistic about any planet being habitable because there are too many requirements to be met," he says. "But Proxima gives us a great chance to find out if I'm right or not."

In light of all this uncertainty, the hype, or as it is now fashionable to call it - hype, about this planet seems premature or just plain wrong. But the hype is definitely there.

“I was surprised when I read an article from the European Southern Observatory, which was very clear that this is the most Earth-like planet we have found so far,” says Lisa Messery, an anthropologist at the University of Virginia, “despite the fact that in in the same article they wrote that the planet has no seasons, the year lasts 11 days, the sky should be red, and Proxima Centauri is an active star with solar flares. In other words: it is generally an uninhabited world.”

Messeri doesn't study exoplanets. She studies people who study the planets - following them and interviewing them for many years. The response to this discovery, she says, has more to do with Proxima's proximity to us. "The reason we care about this planet is because it's a place that we can go to and be." In the case of most planets, we can only imagine. But Proxima Centauri b is the first exoplanet that could become physically reachable.

Earth geography similarly influences our perception. “We feel connected to places that are close to us because we can go there on the weekend,” Messeri says. "Even if I'm not going to New York on Saturday, the fact that I can makes it part of my world."

Forward and with a song

Although scientists are not going to Alpha Centauri on Saturday, they definitely intend to fly there. The Breakthrough Starshot Initiative, which announced in April, plans to send probes the size of a postage stamp to the star. At the time of Proxima's announcement, the people behind the project had not yet determined which star in the triple system they wanted to visit (but now the choice is almost obvious).

True, it is still too early to discuss interstellar space travel - in the sense of seriously discussing it. Scientists try to stay away from such discussions. But now there is a reason and a place to point to, Messeri says. With such a place, scientists can quite honestly and passionately speak publicly about interstellar intentions.

The proximity of the new planet also makes the search for alien life more reasonable. There is a real star, a real earth-like planet, really nearby. If a Contact-style signal came from that system, you could bet a million dollars that the governments of the world would band together and send people there. Because the interstellar human travel to Proxima is the space version of Messeri's weekend trip to New York.

Sending an interstellar message to aliens instead of waiting to receive one has historically been considered a philosophical exercise. A message can take many generations to reach its destination, as can a hypothetical answer. But with Proxima, we get something like a real conversation with aliens, as if meeting with a stranger, says Douglas Vakoch, head of METI International. "In less than a decade, we could send a message and get a response from interested Centauri."

More traditional sciences will also share in the benefits: for example, the European Extremely Large Telescope will be able to take pictures of this planet, which will provide at least a little new information (maybe a lot). It will allow scientists to find possible biosignatures indicating the existence of life. Scientists go crazy at the very thought of such a possibility, because the closer the planet, the more information we can learn about it.

looking in the mirror

And yet it's not Earth's twin, no matter what the headlines say, and scientists haven't found Earth's twins yet. Hot jupiters are cool; planets with glassy rains are also fun; super-earths are generally something supernatural. Compiling a complete census of exoplanets would be a very valuable acquisition. But most scientists, according to Messeri, really just want to find another Earth. This is reflected in scientific priorities. The Kepler space telescope, which has found more planets than anyone else on this planet, was "specially designed to survey part of our region of the Milky Way galaxy in search of dozens of Earth-sized planets in or near the habitable zone," according to NASA.

The search for an "Earth twin" is a pursuit of a Platonic ideal, Messeri says. "It allows us to see the Earth in its prime as we would like to see it, one that is not ravaged by climate change, war or disease."

But we have not yet found such a place. And we may never find it. In your quest to find the perfect match, you usually find someone who is super cool but yells at you when they're hungry or hates your mom. In search of the perfect job, you find yourself in the role of a dishwasher. In this sense, the discovery of Proxima Centauri b is a representation of humanity's desire for perfection, for a pure and virgin Earth.

Most likely, this will happen all the time. We set ourselves a great goal and failed. Not because we are so unlucky, but because we were doomed to it from the very beginning, because this is the nature of humanity: to always strive for the ideal and never achieve it.