How many of them. Scientists announce the discovery of the ninth planet A new celestial body in the solar system

About 30 human-made spacecraft in our solar system are currently collecting information about our planet and its environs. Every year evidence is collected that supports some theories while pushing others to the sidelines. Here are some of the most interesting facts that we managed to learn about our solar system in 2016.

Jupiter and Saturn throw comets at us

In 1994, the entire world watched as comet Shoemaker-Levy 9 crashed into Jupiter and "left an Earth-sized trail that lasted for a year." Then the astronomers happily talked that Jupiter protects us from comets and asteroids.

Thanks to its massive gravitational field, Jupiter was thought to pull in most of these threats before they reach Earth. But a recent study showed that the exact opposite may be true, and this whole "Jupiter shield" idea is not true.

Simulations at NASA's Jet Propulsion Laboratory in Pasadena have shown that Jupiter and Saturn are most likely tossing space debris into the inner solar system and into orbits that put them in the path of Earth. It turns out that the giant planets are bombarding us with comets and asteroids.

The good news is that the comets that bombarded the Earth during its developmental stages may have "carried in volatiles from the outer solar system necessary for the formation of life."

Pluto has liquid water

On the outskirts of the known solar system, NASA's New Horizons spacecraft reveals strange things about the distant dwarf planet Pluto. First of all, it is interesting that Pluto has a liquid ocean.

The presence of fracture lines and analysis of a large crater called Sputnik Planum led the researchers to a model that shows Pluto has a 100-kilometer-thick liquid ocean with a 30% salt content beneath a 300-kilometer-thick shell of ice. It is about as salty as the Dead Sea.

If Pluto's ocean were in the process of freezing, then the planet would have to contract. But it looks like it's expanding. Scientists suspect that there is enough radioactivity left in the core to provide at least some heat. The thick layers of exotic surface ice act as an insulator, and probably the presence of ammonia acts as an antifreeze.

The cores of Neptune and Uranus are wrapped in plastic

How do you know what lies beneath the clouds of distant gas giants, where the atmospheric pressure is nine million times higher than on Earth? Maths! Scientists used the USPEX algorithm to provide a possible picture of what is happening under the clouds of these poorly understood planets.

Knowing that Neptune and Uranus are made up mostly of oxygen, carbon and hydrogen, scientists have plugged in calculations to determine the strange chemical processes that might be taking place there. The result is exotic polymers, organic plastics, crystalline carbon dioxide, and orthocarbon acid (aka "Hitler's acid" because its atomic structure resembles a swastika) wrapped around a solid inner core.

While searching for extraterrestrial life on Titan and Europa, scientists hope that water may have reacted with rocks in organic processes. But if the inner core is wrapped in exotic crystals and plastics, some things will have to be reconsidered.

Mercury has a huge Grand Canyon

If there was volcanic activity on Venus and Mars even a few million years ago, it looks like baby Mercury calmed down 3-4 billion years ago. The planet cooled down, began to shrink and crack.

In the process, a massive crack appeared, which scientists call the "big valley." According to University of Maryland scientists:

“The valley is 400 kilometers wide and 965 kilometers long, with steep slopes that penetrate 3 kilometers below the surrounding terrain. For comparison, if the "big valley" of Mercury existed on Earth, it would be twice as deep as the Grand Canyon and stretch from Washington DC to New York and Detroit far to the west."

On a tiny planet with a circumference of only 4,800 kilometers, such a large valley looks more like a terrible scar on the face.

Venus was once habitable

Venus is the only planet that spins backwards. At 460 degrees Celsius, its surface is hot enough to melt lead, and the planet itself is shrouded in clouds of sulfuric acid. But one day, Venus may have been able to support life.

More than four billion years ago, Venus had oceans. In fact, it is believed that there has been water on the planet for over two billion years. Today, Venus is very dry and has no water vapor at all. The Sun's solar wind blew it all away.

The atmosphere of Venus gives off a large electric field five times stronger than the earth's. This field is also strong enough to overcome the gravity of Venus and push hydrogen and oxygen into the upper atmosphere, where the solar winds blow them away.

Scientists don't know why Venus's electric field is so strong, but it could be because Venus is closer to the Sun.

The earth is fueled by the moon

The Earth is surrounded by a magnetic field that protects us from charged particles and harmful radiation. If not for it, we would be exposed to cosmic rays 1000 times stronger than those that are now. Our computers and electronics would fry instantly. Therefore, it is great that a giant ball of molten iron is spinning in the center of our planet. Until recently, scientists weren't sure why it kept spinning. Eventually, it should cool down and slow down.

But over the past 4.3 billion years, it has cooled by only 300 degrees Celsius. Thus, we lost quite a bit of heat, which did not play a special role for the magnetic field. Scientists now believe that the Moon's orbit is supporting Earth's hot core as it rotates, injecting about 1,000 billion watts of energy into the core. The moon may be more important to us than we thought.

The rings of Saturn are new

Since the 1600s, there has been debate about how many Saturn's rings exist and where they came from. In theory, Saturn once had more moons and some of them collided with each other. As a result, a cloud of debris appeared, which decomposed into rings and 62 satellites.

By watching Saturn squeezing geysers out of Enceladus, scientists were able to estimate the relative strength of the gas giant's tug. Since all the satellites were thrown into longer orbits, this allowed scientists to roughly estimate when the cabal among the moons occurred.

The numbers showed that Saturn's rings had nothing to do with the formation of the planet four billion years ago. In fact, with the exception of the more distant moons of Titan and Iapetus, Saturn's large moons appear to have formed during the Cretaceous period, the age of the dinosaurs.

There are 15,000 very large asteroids in our vicinity.

In 2005, NASA was tasked with finding 90% of large objects in near-Earth space by 2020. So far, the agency has found 90% of objects that are 915 meters or larger, but only 25% are 140 meters or larger.

In 2016, with 30 new discoveries per week, NASA discovered its 15,000 objects. For reference: in 1998, the agency found only 30 new objects per year. NASA catalogs all the comets and asteroids around to make sure we know when something is about to hit us. However, meteors sometimes erupt without warning, like the one that exploded over Chelyabinsk in 2013.

We deliberately crashed the device on a comet

The European Space Agency's Rosetta spacecraft orbited comet 67P/Churyumov-Gerasimenko for two years. The device collected data and even placed the lander on the surface, although not entirely successfully.

This 12-year mission has led to a number of important discoveries. For example, Rosetta discovered the amino acid glycine, the basic building block of life. Although it has long been assumed that amino acids could have formed in space at the dawn of the solar system, they were only discovered thanks to Rosetta.

Rosetta found 60 molecules, 34 of which had never been found on a comet before. The spacecraft's instruments also showed a significant difference in the composition of the comet's water and Earth's water. It turns out that it is unlikely that water on Earth appeared due to comets.

After a successful mission, the ESA crashed the craft into a comet.

Mysteries of the Sun solved

All planets and stars have magnetic fields that change over time. On Earth, these fields turn over every 200,000-300,000 years. But now they are late.

Everything happens faster in the Sun. Every 11 years or so, the polarity of the Sun's magnetic field reverses. This is accompanied by a period of increased solar activity and sunspots.

Oddly enough, Venus, Earth and Jupiter align at this time. Scientists believe that these planets can influence the Sun. As the planets align, their gravity combines to cause a tidal effect on the sun's plasma, pulling it in and disrupting the sun's magnetic field, the study found.

Scientists at the California Institute of Technology announced the discovery. So far, no one has seen a new object through a telescope. According to Michael Brown and Konstantin Batygin, the planet was discovered by analyzing data on the gravitational perturbation it exerts on other celestial bodies. The name has not yet been given to her, but scientists have been able to determine various parameters. It weighs 10 times more than the Earth. The chemical composition of the new planet resembles two gas giants - Uranus and Neptune. By the way, it is similar to Neptune in its size, and is even further from the sun than Pluto, which, due to its modest size, has lost its status as a planet. Confirmation of the existence of a celestial body will take five years. Scientists have booked time at a Japanese observatory in Hawaii. The probability that their discovery is wrong is 0.007 percent. The new planet, if the discovery is recognized, will be the ninth in the solar system.

The solar system appears to have a new ninth planet. Today, two scientists announced evidence that a body nearly the size of Neptune-but as yet unseen-orbits the sun every 15,000 years. During the solar system's infancy 4.5 billion years ago, they say, the giant planet was knocked out of the planet-forming region near the sun. Slowed down by gas, the planet settled into a distant elliptical orbit, where it still lurks today.

The claim is the strongest yet in the centuries-long search for a "Planet X" beyond Neptune. The quest has been plagued by far-fetched claims and even outright quackery. But the new evidence comes from a pair of respected planetary scientists, Konstantin Batygin and Mike Brown of the California Institute of Technology (Caltech) in Pasadena, who prepared for the inevitable skepticism with detailed analyzes of the orbits of other distant objects and months of computer simulations. “If you say, ‘We have evidence for Planet X,’ almost any astronomer will say, ‘This again? These guys are clearly crazy.’ I would, too,” Brown says. Why is this different? This is different because this time we're right."

LANCE HAYASHIDA/CALTECH

Outside scientists say their calculations stack up and express a mixture of caution and excitement about the result. “I could not imagine a bigger deal if-and of course that’s a boldface ‘if’-if it turns out to be right,” says Gregory Laughlin, a planetary scientist at the University of California (UC), Santa Cruz. "What's thrilling about it is detectable."

Batygin and Brown inferred its presence from the peculiar clustering of six previously known objects that orbit beyond Neptune. They say there's only a 0.007% chance, or about one in 15,000, that the clustering could be a coincidence. Instead, they say, a planet with the mass of 10 Earths has shepherded the six objects into their strange elliptical orbits, tilted out of the plane of the solar system.

The orbit of the inferred planet is similarly tilted, as well as stretched to distances that will explode previous conceptions of the solar system. Its closest approach to the sun is seven times farther than Neptune, or 200 astronomical units (AUs). (An AU is the distance between Earth and the sun, about 150 million kilometers.) And Planet X could roam as far as 600 to 1200 AU, well beyond the Kuiper belt, the region of small icy worlds that begins at Neptune's edge about 30 AU.

If Planet X is out there, Brown and Batygin say, astronomers ought to find more objects in telltale orbits, shaped by the pull of the hidden giant. But Brown knows that no one will really believe in the discovery until Planet X itself appears within a telescope viewfinder. "Until there's a direct detection, it's a hypothesis-even a potentially very good hypothesis," he says. The team has time on the one large telescope in Hawaii that is suited for the search, and they hope other astronomers will join in the hunt.

Batygin and Brown published the result today in The Astronomical Journal. Alessandro Morbidelli, a planetary dynamicist at the Nice Observatory in France, performed the peer review for the paper. In a statement, he says Batygin and Brown made a "very solid argument" and that he is "quite convinced by the existence of a distant planet."

Championing a new ninth planet is an ironic role for Brown; he is better known as a planet slayer. His 2005 discovery of Eris, a remote icy world nearly the same size as Pluto, revealed that what was seen as the outermost planet was just one of many worlds in the Kuiper belt. Astronomers promptly reclassified Pluto as a dwarf planet-a saga Brown recounted in his book How I Killed Pluto.

Now, he has joined the centuries-old search for new planets. His method-inferring the existence of Planet X from its ghostly gravitational effects-has a respectable track record. In 1846, for example, the French mathematician Urbain Le Verrier predicted the existence of a giant planet from irregularities in the orbit of Uranus. Astronomers at the Berlin Observatory found the new planet, Neptune, where it was supposed to be, sparking a media sensation.

Remaining hiccups in Uranus's orbit led scientists to think that there might yet be one more planet, and in 1906 Percival Lowell, a wealthy tycoon, began the search for what he called "Planet X" at his new observatory in Flagstaff, Arizona. In 1930, Pluto turned up-but it was far too small to tug meaningfully on Uranus. More than half a century later, new calculations based on measurements by the Voyager spacecraft revealed that the orbits of Uranus and Neptune were just fine on their own: No Planet X was needed.

Yet the allure of Planet X persisted. In the 1980s, for example, the researchers proposed that an unseen brown dwarf star could cause periodic extinctions on Earth by triggering fusillades of comets. In the 1990s, scientists invoked a Jupiter-sized planet at the solar system’s edge to explain the origin of certain oddball comets. Just last month, researchers claimed to have detected the faint microwave glow of an outsized rocky planet some 300 AU away, using an array of telescope dishes in Chile called the Atacama Large Millimeter Array (ALMA). (Brown was one of many skeptics, noting that ALMA's narrow field of view made the chances of finding such an object vanishingly slim.)

Brown got his first inkling of his current quarry in 2003, when he led a team that found Sedna, an object a bit smaller than both Eris and Pluto. Sedna's odd, far-flung orbit made it the most distant known object in the solar system at the time. Its perihelion, or closest point to the sun, lay at 76 AU, beyond the Kuiper belt and far outside the influence of Neptune's gravity. The implication was clear: Something massive, well beyond Neptune, must have pulled Sedna into its distant orbit.

(DATA)JPL; BATYGIN AND BROWN/CALTECH; (DIAGRAM) A. CUADRA/ SCIENCE

That something didn't have to be a planet. Sedna’s gravitational nudge could have come from a passing star, or from one of the many other stellar nurseries that surrounded the nascent sun at the time of the solar system’s formation.

Since then, a handful of other icy objects have turned up in similar orbits. By combining Sedna with five other weirdos, Brown says he has ruled out stars as the unseen influence: Only a planet could explain such strange orbits. Of his three major discoveries-Eris, Sedna, and now, potentially, Planet X-Brown says the last is the most sensational. Killing Pluto was fun. Finding Sedna was scientifically interesting,” he says. "But this one, this is head and shoulders above everything else."

Brown and Batygin were nearly beaten to the punch. For years, Sedna was a lone clue to a perturbation from beyond Neptune. Then, in 2014, Scott Sheppard and Chad Trujillo (a former graduate student of Brown’s) published a paper describing the discovery of VP113, another object that never comes close to the sun. Sheppard, of the Carnegie Institution for Science in Washington, D.C., and Trujillo, of the Gemini Observatory in Hawaii, were well aware of the implications. They began to examine the orbits of the two objects along with 10 other oddballs. They noticed that, at perihelion, all came very near the plane of solar system in which Earth orbits, called the ecliptic. In a paper, Sheppard and Trujillo pointed out the peculiar clumping and raised the possibility that a distant large planet had herded the objects near the ecliptic. But they didn't press the result any further.

Later that year, at Caltech, Batygin and Brown began discussing the results. Plotting the orbits of the distant objects, Batygin says, they realized that the pattern that Sheppard and Trujillo had noticed "was only half of the story." Not only were the objects near the ecliptic at perihelia, but their perihelia were physically clustered in space (see diagram, above).

For the next year, the duo secretly discussed the pattern and what it meant. It was an easy relationship, and their skills complemented each other. Batygin, a 29-year-old whiz kid computer modeler, went to college at UC Santa Cruz for the beach and the chance to play in a rock band. But he made his mark there by modeling the fate of the solar system over billions of years, showing that, in rare cases, it was unstable: Mercury may plunge into the sun or collide with Venus. "It was an amazing accomplishment for an undergraduate," says Laughlin, who worked with him at the time.

Brown, 50, is the observational astronomer, with a flair for dramatic discoveries and the confidence to match. He wears shorts and sandals to work, puts his feet up on his desk, and has a breeziness that masks intensity and ambition. He has a program all set to sift for Planet X in data from a major telescope the moment they become publicly available later this year.

Their offices are a few doors down from each other. "My couch is nicer, so we tend to talk more in my office," Batygin says. "We tend to look more at data in Mike's." They even became exercise buddies, and discussed their ideas while waiting to get in the water at a Los Angeles, California, triathlon in the spring of 2015.

First, they winnowed the dozen objects studied by Sheppard and Trujillo to the six most distant-discovered by six different surveys on six different telescopes. That made it less likely that the clumping might be due to an observation bias such as pointing a telescope at a particular part of the sky.

Batygin began seeding his solar system models with Planet X’s of various sizes and orbits, to see which version best explained the objects’ paths. Some of the computer runs took months. A favored size for Planet X emerged-between five and 15 Earth masses-as well as a preferred orbit: antialigned in space from the six small objects, so that its perihelion is in the same direction as the six objects' aphelion, or farthest point from the sun. The orbits of the six cross that of Planet X, but not when the big bully is nearby and could disrupt them. The final epiphany came 2 months ago, when Batygin's simulations showed that Planet X should also sculpt the orbits of objects that swoop into the solar system from above and below, nearly orthogonal to the ecliptic. "It sparked this memory," Brown says. "I've seen these objects before." It turns out that, since 2002, five of these highly inclined Kuiper belt objects have been discovered, and their origins are largely unexplained. "Not only are they there, but they are in exactly the places we predicted," Brown says. "That is when I realized that this is not just an interesting and good idea-this is actually real."

Sheppard, who with Trujillo had also suspected an unseen planet, says Batygin and Brown “took our result to the next level. …They got deep into the dynamics, something that Chad and I aren’t really good with. That's why I think this is exciting."

Others, like planetary scientist Dave Jewitt, who discovered the Kuiper belt, are more cautious. The 0.007% chance that the clustering of the six objects is coincidental gives the planet claim a statistical significance of 3.8 sigma-beyond the 3-sigma threshold typically required to be taken seriously, but short of the 5 sigma that is sometimes used in fields like particle physics. That worries Jewitt, who has seen plenty of 3-sigma results disappear before. By reducing the dozen objects examined by Sheppard and Trujillo to six for their analysis, Batygin and Brown weakened their claim, he says. "I worry that the finding of a single new object that is not in the group would destroy the whole edifice," says Jewitt, who is at UC Los Angeles. "It's a game of sticks with only six sticks."

(IMAGES) WIKIMEDIA COMMONS; NASA/JPL-CALTECH; A. CUADRA/ SCIENCE ; NASA/JHUAPL/SWRI; (DIAGRAM) A. CUADRA/ SCIENCE

At first blush, another potential problem comes from NASA’s Widefield Infrared Survey Explorer (WISE), a satellite that completed an all-sky survey looking for the heat of brown dwarfs-or giant planets. It ruled out the existence of a Saturn-or-larger planet as far out as 10,000 AU, according to a 2013 study by Kevin Luhman, an astronomer at Pennsylvania State University, University Park. But Luhman notes that if Planet X is Neptune-sized or smaller, as Batygin and Brown say, WISE would have missed it. He says there is a slim chance of detection in another WISE data set at longer wavelengths-sensitive to cooler radiation-which was collected for 20% of the sky. Luhman is now analyzing those data.

Even if Batygin and Brown can convince other astronomers that Planet X exists, they face another challenge: explaining how it ended up so far from the sun. At such distances, the protoplanetary disk of dust and gas was likely to have been too thin to fuel planet growth. And even if Planet X did get a foothold as a planetesimal, it would have moved too slowly in its vast, lazy orbit to hoover up enough material to become a giant.

Instead, Batygin and Brown propose that Planet X formed much closer to the sun, alongside Jupiter, Saturn, Uranus, and Neptune. Computer models have shown that the early solar system was a tumultuous billiards table, with dozens or even hundreds of planetary building blocks the size of Earth bouncing around. Another embryonic giant planet could easily have formed there, only to be booted outward by a gravitational kick from another gas giant.

It’s harder to explain why Planet X didn’t either loop back around to where it started or leave the solar system entirely. But Batygin says that residual gas in the protoplanetary disk might have exerted enough drag to slow the planet just enough for it to settle into a distant orbit and remain in the solar system. That could have happened if the ejection took place when the solar system was between 3 million and 10 million years old, he says, before all the gas in the disk was lost into space.

Hal Levison, a planetary dynamicist at the Southwest Research Institute in Boulder, Colorado, agrees that something has to be creating the orbital alignment Batygin and Brown have detected. But he says the origin story they have developed for Planet X and their special pleading for a gas-slowed ejection add up to "a low-probability event." Other researchers are more positive. The proposed scenario is plausible, Laughlin says. "Usually things like this are wrong, but I'm really excited about this one," he says. "It's better than a coin flip."

All this means that Planet X will remain in limbo until it is actually found.

Astronomers have some good ideas about where to look, but spotting the new planet won't be easy. Because objects in highly elliptical orbits move fastest when they are close to the sun, Planet X spends very little time at 200 AU. And if it were there right now, Brown says, it would be so bright that astronomers probably would have already spotted it.

Instead, Planet X is likely to spend most of its time near aphelion, slowly trotting along at distances between 600 and 1200 AU. Most telescopes capable of seeing a dim object at such distances, such as the Hubble Space Telescope or the 10-meter Keck telescopes in Hawaii, have extremely tiny fields of view. It would be like looking for a needle in a haystack by peering through a drinking straw.

One telescope can help: Subaru, an 8-meter telescope in Hawaii that is owned by Japan. It has enough light-gathering area to detect such a faint object, coupled with a huge field of view-75 times larger than that of a Keck telescope. That allows astronomers to scan large swaths of the sky each night. Batygin and Brown are using Subaru to look for Planet X-and they are coordinating their efforts with their erstwhile competitors, Sheppard and Trujillo, who have also joined the hunt with Subaru. Brown says it will take about 5 years for the two teams to search most of the area where Planet X could be lurking.

Subaru Telescope, NAOJ

If the search pans out, what should the new member of the sun's family be called? Brown says it's too early to worry about that and scrupulously avoids offering up suggestions. For now, he and Batygin are calling it Planet Nine (and, for the past year, informally, Planet Phattie-1990s slang for "cool"). Brown notes that neither Uranus nor Neptune-the two planets discovered in modern times-ended up being named by their discoverers, and he thinks that that's probably a good thing. It's bigger than any one person, he says: "It's kind of like finding a new continent on Earth."

He is sure, however, that Planet X-unlike Pluto-deserves to be called a planet. Something the size of Neptune in the solar system? Don't even ask. "No one would argue this one, not even me."

The structure of the solar system is quite simple. At its center is the Sun - a star ideal for the development of life: not too hot, but not too cold, not too bright, but not too dim, with a long lifetime and very moderate activity. Closer to the Sun are the planets of the terrestrial group, which, in addition to the Earth, includes Mercury, Venus and Mars. These planets are relatively low-mass, but are composed of stony rocks, which allows them to have a solid surface. In recent years, the concept of the habitable zone is gaining popularity: this is the name for the distance interval from the central star, within which liquid water can exist on the surface of a terrestrial planet. In the solar system, the habitable zone stretches roughly from the orbit of Venus to the orbit of Mars, but only Earth can boast of liquid water (at least in significant quantities).

Further from the Sun are the giant planets (Jupiter and Saturn) and the ice giants (Uranus and Neptune). The giants are significantly more massive than the terrestrial planets, but this mass is gained by them due to volatile compounds, which is why the giants are significantly less dense and lack a solid surface. Between the last planet of the terrestrial group - Mars - and the first giant planet - Jupiter - is the main asteroid belt; behind the last ice giant - Neptune - the periphery of the solar system begins. Previously, there was another planet, Pluto, but in 2006 the world astronomical community decided that Pluto did not live up to a real planet in terms of its parameters, and now the most distant planet in the solar system (known!) Is Neptune, orbiting 30 AU . from the Sun (more precisely, from 29.8 AU at perihelion to 30.4 AU at aphelion).

However, for quite a long time, many scientists have not left the idea that the number of planets in the solar system does not stop on Neptune. True, the farther the planet is from the Sun, the more difficult it is to detect it directly, but there are also indirect ways. One is to look for the gravitational influence of an invisible planet on the known bodies of the trans-Neptunian region. In particular, attempts have been repeatedly made, firstly, to find patterns in the orbits of long-period comets, and secondly, to explain these patterns by the attraction of a distant giant planet. In more extremist versions, the apparent periodicity in the extinction of living organisms on Earth or in the frequency of meteorite bombardment of our planet is considered a sign of the presence of a distant planet. However, until now, assumptions about unknown planets (Nemesis, Tyukhe, etc.), based on these regularities and periodicities, have not found wide recognition among the astronomical community. Not only the explanation, but the very existence of the regularities and periodicities to be explained seems rather unconvincing. In addition, as a rule, we are talking about fairly large bodies, perhaps many times more massive than Jupiter, which should be accessible to modern observational technology.

A new attempt to prove the existence of the ninth planet is also based on the search for signs of its gravitational influence, but not on long-period comets, but on Kuiper belt objects.

Kuiper belt

The Kuiper belt is sometimes collectively referred to as all the objects inhabiting the periphery of the solar system. But in fact, they are several dynamically distinct groups: the classical Kuiper belt, the scattered disk, and resonant objects. The objects of the classical Kuiper belt revolve around the Sun in orbits with small inclinations and eccentricities, that is, in orbits of the "planetary" type. Scattered disk objects move in elongated orbits with perihelia in the region of Neptune's orbit, the orbits of resonant objects (Pluto among them) are in orbital resonance with Neptune.
The classical Kuiper belt ends rather abruptly at about 50 AU. Probably, it was there that the main boundary of the distribution of matter in the solar system passed. And although objects of the scattered disk and resonant objects at aphelion (the point of the orbit of a celestial body farthest from the Sun) move away from the Sun by hundreds of astronomical units, at perihelion (the point of the orbit closest to the Sun) they are close to Neptune, indicating that both are connected common origin with the classical Kuiper belt, and were “attached” to their modern orbits by the gravitational influence of Neptune.

Discovery of Sedna

The picture began to get more complicated in 2003, when the trans-Neptunian object (TNO) Sedna was discovered with a perihelion distance of 76 AU. Such a significant distance from the Sun means that Sedna could not get into its orbit as a result of interaction with Neptune, and therefore there was an assumption that it is a representative of a more distant population of the solar system - the hypothetical Oort cloud.

For some time, Sedna was the only known object with such an orbit. The discovery of the second "sednoid" in 2014 was reported by Chadwick Trujillo and Scott Sheppard. The object 2012 VP113 revolves around the Sun in an orbit with a perihelion distance of 80.5 AU, that is, even more than that of Sedna. Trujillo and Sheppard noticed that both Sedna and 2012 VP113 have similar values ​​of the perihelion argument - the angle between the directions to the perihelion and to the ascending node of the orbit (the point of its intersection with the ecliptic). Interestingly, similar values ​​of the perihelion argument (340° ± 55°) are characteristic of all objects with semi-major axes greater than 150 AU. and with perihelion distances greater than Neptune's perihelion distance. Trujillo and Sheppard suggested that such a grouping of objects near a particular value of the perihelion argument could be caused by the perturbing action of a distant massive (several Earth masses) planet.

Evidence for Planet X

A paper published in January 2016 by Konstantin Batygin and Michael Brown of the California Institute of Technology explores the possibility that the existence of a previously unknown planet can indeed explain the observed parameters of distant asteroids with similar values ​​of the perihelion argument. The authors analytically and numerically studied the motion of test particles at the periphery of the Solar System over a period of 4 billion years under the influence of a perturbing body with a mass of 10 Earth masses in an elongated orbit and showed that the presence of such a body actually leads to the observed configuration of TNO orbits with significant semi-major axes and perihelion distances. Moreover, the presence of an outer planet makes it possible to explain not only the existence of Sedna and other TNOs with similar values ​​of the perihelion argument.
Unexpectedly for the authors in their simulations, the action of the perturbing body explained the existence of another TNO population, the origin of which has so far remained unclear, namely, the population of Kuiper belt objects in orbits with high inclinations. Finally, the work of Batygin and Brown predicts the existence of objects with large perihelion distances and other values ​​of the perihelion argument, which provides an additional observational verification of their prediction.

Prospects for the discovery of a new planet

The main test of recent research, of course, should be the discovery of the "troublemaker" itself - the very planet whose attraction, according to the authors, determines the distribution of bodies with perihelions outside the classical Kuiper belt. The task of finding it is very difficult. Planet X should spend most of the time near aphelion, which can be over 1000 AU away. from the sun. Calculations indicate the possible location of the planet very approximately - its aphelion is located approximately in the direction opposite to the direction on the aphelions of the studied TNOs, but the orbital inclination cannot be determined from the data on the available TNOs with semi-major axes of the orbits. So the review of a very large area of ​​​​the sky, where an unknown planet may be located, will last for many years. The search may become easier if other TNOs moving under the influence of Planet X are discovered, which will narrow the range of possible values ​​for its orbital parameters.

WISE (Wide-Field Infrared Survey Explorer), a NASA space telescope launched in 2009 to study the sky in the infrared, could not see a hypothetical planet. An analogue of Saturn or Jupiter, WISE would detect at a distance of up to 30,000 AU, that is, more than necessary. But the estimates were carried out specifically for the giant planet with the corresponding own IR radiation. It is possible that these results do not scale to an ice giant like Neptune or even a less massive planet.
There is currently, in fact, one telescope suitable for searching for Planet X, and that is the Japanese Subaru Telescope in the Hawaiian Islands. Thanks to the 8.2-meter mirror, it collects a lot of light and therefore has a high sensitivity, while its equipment allows you to take pictures of fairly large areas of the sky (approximately the area of ​​the full moon). But even under these conditions, it will take several years to survey the vast area of ​​the sky where Planet X may be now. If it fails, one can only hope for a specialized survey telescope LSST, which is currently under construction in Chile. With a mirror with a diameter of 8.4 meters, it will have a field of view with a diameter of 3.5 ° (seven times larger than that of the Subaru). At the same time, survey observations will be its main task, unlike Subaru, which operates on numerous observational programs. The commissioning of the LSST is expected in the early 2020s.

On February 29, March 2 and 4, the PostNauka Academy on the Old Arbat will host Vladimir Surdin's intensive "Solar System: In Search of a Spare Planet" - 9 classes that will help you understand the diversity of planets and find out if, in addition to the Earth, there are planets suitable for life .