Caltech scientists Michael Brown and Konstantin Batygin have provided evidence for the existence of a giant planet in the solar system, located even further from the Sun than Pluto.
The researchers reported that they have not yet been able to see it through a telescope. According to them, the planet was discovered when studying the movement of small celestial bodies in deep space. The mass of the celestial body is about 10 times the mass of the Earth, but scientists have yet to verify its existence.
Institute astronomers have only a rough idea of where the planet might be in the starry sky, and no doubt their suggestion will launch a campaign to find it.
"There are many telescopes on Earth theoretically capable of finding it. I really hope that now, after our announcement, people around the world will start looking for the ninth planet," said Michael Brown.
Elliptical orbit
According to scientists, the space object is about 20 times farther from the Sun than Neptune, which is 4.5 billion km away.
Unlike the almost circular orbits of other planets in the Solar System, this object is supposed to move in an elliptical orbit, and a complete revolution around the Sun takes from 10 thousand to 20 thousand years.
Scientists have studied the movement of objects consisting mainly of ice in the Kuiper Belt. Pluto is in this belt.
The researchers noticed a certain location of some bodies in the Belt, in particular such large objects as Sedna and 2012 VP113. In their opinion, this can only be explained by the presence of an unknown large space object.
"All the most distant objects move in the same direction on an inexplicable trajectory, and we realized that the only explanation for this is the existence of a large, distant planet that holds them together as they orbit the Sun," Brown said.
Planet X
The idea of the existence of the so-called Planet X, located on the periphery of the solar system, has been discussed in scientific circles for more than 100 years. She is remembered and then forgotten.
The current speculation is of particular interest because of the study's lead author.
Brown specializes in searching for distant objects, and it was his discovery of the dwarf planet Eris in the Kuiper Belt in 2005 that led to Pluto losing planetary status a year later. Then it was assumed that Eris is slightly larger than Pluto, but now it has become clear that it is slightly smaller than it.
Researchers studying distant objects in the solar system have been speculating for some time on the possibility of a planet the size of Mars or Earth due to the size and shape of the planets in the Kuiper Belt. But until you can see the planet through a telescope, the idea of its existence will be perceived with skepticism.
The study by Michael Brown and Konstantin Batygin was published in the Astronomical Journal.
In 2006, Pluto was stripped of its status as the ninth planet in the solar system thanks to the efforts of one astronomer, Michael Brown. Together with his colleagues, he discovered, and then other dwarf planets far beyond the orbit of Neptune. Thus, he proved that Pluto is not remarkable and big enough to be called a full-fledged planet. However, now Brown and our compatriot Konstantin Batygin are claiming that the new Planet 9 is already almost open ... and that all that remains is to see it.
Yes, yes, no one has yet seen the “almost open” ninth planet of the solar system! In fact, its discovery is the fruit of long observations of the orbits of other planets. According to Kepler and Newton, the place of each planet in the solar system is determined by its characteristics, mainly by mass. And if the orbit does not correspond to the parameters of the planet or is generally anomalous, then it is influenced by some other, no less massive object. The first planet discovered by mathematical equations, and not live observations, was - in 1846 it was found at a place calculated by the French mathematician Urbain Le Verrier.
Moreover, the planets can influence each other very actively - in the past of the solar system they traveled hundreds of millions of kilometers, approaching and moving away from the Sun. The gas giants were especially distinguished here. In young planetary systems, they absorb all the embryos of the planets and hang close to the star - as close as Mercury. Because of this, they become very hot and become unstable. Scientists call such planets "hot Jupiters" or "hot Neptunes" - depending on their mass and size.
Troubled History of the Solar System
However, Jupiter, the largest and most influential planet, changed everything in the solar system. Initially appearing at a distance of 5 to 10 from the Sun, it provoked active collisions of scattered material in the protoplanetary disk around the star. This gave impetus to the creation of other gas giants, such as Saturn or Neptune, at distances equally close to the Sun.
However, the newly formed planets behaved "ungratefully", following the laws of gravity - they pushed their "parent" closer to the Sun, into the modern orbit of Mars. Thus, Jupiter invaded the inner part of the solar system. In other planetary systems, this part is the most saturated with matter and space objects. But the heavy tread of the mass of Jupiter scattered the embryos of planets and asteroids there, throwing them into the nuclear furnace of the Sun or throwing them to the outskirts of the system in the zone of modern and.
If not for Saturn, which bound Jupiter with an orbital resonance and did not bring it into a modern orbit, the gas giant could completely ruin the solar system, throwing out 99% of the planetary matter from it. However, his travels did not go unnoticed - so Neptune and Uranus changed their orbits, forming most of the long-period comets.
Ultimately, an unusual balance reigned in the solar planetary system - gas giants that form near the star ended up on the outskirts, and "solid planets" like the Earth migrated closer to the Sun. However, some astronomers believed that another planet was needed to achieve such a balance - and one massive enough to influence the large Neptune and Uranus. It, Planet X, was searched for by many astronomers for a century and a half - and it seems that Brown and Batygin finally got close to it.
History of the search for planet X
After Le Verrier calculated Neptune from perturbations in Uranus's orbit, astronomers found that even its presence did not explain the features of the ice giant's orbit. For some time they tried to find another planet that could influence the last large objects of the solar system - however, they managed to find only Pluto, which, by mass and direction of the orbit, could not disturb larger bodies in any way. The issue of Uranus-Neptune anomalies was finally resolved by "", who measured the mass of Neptune in 1989 and thereby found that there are no contradictions in the orbits.
By that time, the power of telescopes had grown significantly, which allowed astronomers to look into the depths of the solar system. Many trans-Neptunian objects have been discovered - dwarf planets and large asteroids, whose closest orbital point is further from the Sun than Neptune. So, in 2005, the already mentioned Eris was discovered, the second largest dwarf planet after Pluto. And in 2003 they found an object with diameters over 2 thousand kilometers, which moves away from the Sun at a distance of 1.4 × 10 11 km - further than any large trans-Neptunian object! It soon acquired a whole family of "sednoids", isolated trans-Neptunian objects with similar characteristics.
The ninth planet - where and why?
Observing the newly discovered planetoids, astronomers C. Trujillo and S. Sheppard, colleagues, discovered an interesting pattern. Most of them have elongated, comet-like orbits that briefly come "close" to the Sun, at a distance of 40 to 70 astronomical units, and then move away for hundreds or even thousands of years. And the larger the object, the stronger its removal. In addition, the sednoids deviated from the Sun in the same direction.
Such a coincidence could be an accident, if we are talking about simple comets - over the billions of years of the history of the solar system, they were scattered by all the major planets, especially the already mentioned "travelers" Jupiter, Uranus and Neptune. However, for such a coincidence in the deviations of large objects, a very large planet is needed, whose orbit would reach the Oort cloud.
Here Brown and Batygin distinguished themselves - by comparing the orbital characteristics of sednoids, they found mathematically that the probability of their random coincidence is only 0.007%. Scientists went further and compiled a computer model aimed at finding the characteristics of the planet, capable of changing the orbits of bodies located beyond Neptune. The data they received in January 2016 became the basis for the announcement of the pre-discovery of a new planet in the solar system.
Characteristics of Planet X
In his interviews, Brown claims that the probability of finding a new planet is 90%. However, until it is actually discovered, with the help of a telescope, it is too early to talk about the final discovery. Nevertheless, the calculated characteristics of Planet 9 have been published - they will be used in future searches.
- The orbital parameters of Planet X will be mirrored to those of the sednoids - the orbit of the planet will still be elongated and inclined relative to the plane of the main planets of the solar system, but directed in the opposite direction. Accordingly, the perihelion of the planet - the point of maximum approach to the Sun - will be 200 astronomical units at the nearest point, and the aphelion - the maximum distance - will reach 1200 astronomical units. This is even more than Sedna! A year on Planet 9 will last up to 20,000 Earth years, which is how long it may take to complete the entire orbit.
A planet distant from the Sun is difficult to detect - this requires telescopes operating in the infrared spectrum, or powerful optical devices that can capture even the smallest sun glare on the surface. On infrared telescopes, work will move faster, but errors are possible - and on optical telescopes, the result will be reliable, albeit at the cost of time. The WISE Infrared Orbiting Telescope, which conducted broadband surveys in 2009, has yet to detect Planet X, although it has provided fairly detailed images.
Therefore, Brown, Batygin and other astronomers are planning to find it using the Subaru telescop in the Hawaiian Islands, which is considered one of the largest and highest quality in the world - the diameter of its main mirror exceeds 8 meters! In addition, it is capable of operating both in the optical and in the infrared ranges of light. But even with such a tool, it will take scientists at least 5 years to put an end to the issue of Planet X.
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 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 typical for 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 disturbing 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) - NASA's 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 works 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 Old Arbat will host an intensive course by Vladimir Surdin "The 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 .
MOSCOW, January 21 - RIA Novosti. Konstantin Batygin, who discovered at the "tip of the pen" the ninth planet, located 274 times farther from the Sun than the Earth, believes that it is the last real planet in the solar system, the press service of the California Institute of Technology reports.
Last night, Russian astronomer Konstantin Batygin and his American colleague Michael Brown announced that they had managed to calculate the position of the mysterious "planet X" - the ninth, or tenth, if you count Pluto - the planet of the solar system, 41 billion kilometers away from the Sun and weighing 10 times larger than Earth.
“Although we were initially quite skeptical, when we found hints of the existence of another planet in the Kuiper belt, we continued to study its proposed orbit. Over time, we became more and more confident that it really exists. For the first time in the last 150 years, we have real evidence that we have completely completed the "census" of the planets of the solar system, "said Batygin, whose words are quoted by the press service of the magazine.
This discovery, according to Batygin and Brown, was largely due to the discovery of two other ultra-distant "inhabitants" of the solar system - dwarf planets 2012 VP113 and V774104, comparable in size to Pluto and removed from the Sun by about 12-15 billion kilometers.
Both of these planets were discovered by Chad Trujillo of the Gemini Observatory in the Hawaiian Islands (USA), a student of Brown, who, after their discovery, shared with his teacher and Batygin his observations, indicating oddities in the movement of Biden, as 2012 VP113 was called , and a number of other Kuiper objects.
Astronomers have announced the discovery of another contender for the title of the most distant inhabitant of the solar system - the dwarf planet V774104 with a diameter of 500-1000 kilometers, located 15 billion kilometers from the Sun.An analysis of the orbits of these objects showed that some large celestial body acts on them all, forcing the orbits of these small dwarf planets and asteroids to stretch in a certain direction, the same for at least six objects from the list presented by Trujillo. In addition, the orbits of these objects were inclined to the plane of the ecliptic at the same angle - approximately 30%.
This "coincidence," scientists explain, is like clockwork moving at different speeds and pointing to the same minute every time you look at it. The probability of such an outcome of events is 0.007%, which indicates that the orbits of the "inhabitants" of the Kuiper belt were not extended by chance - they were "conducted" by some large planet located far beyond the orbit of Pluto.
Batygin's calculations show that this is definitely a "real" planet - its mass is 5 thousand times greater than that of Pluto, which most likely means that it is a gas giant like Neptune. A year on it lasts about 15 thousand years.
It rotates in an unusual orbit - its perihelion, the point of closest approach to the Sun, is located on the "side" of the solar system, where the aphelion is located - the point of maximum removal - for all other planets.
Such an orbit paradoxically stabilizes the Kuiper belt, preventing its objects from colliding with each other. So far, astronomers have not been able to see this planet because of its remoteness from the Sun, but Batygin and Brown believe that this will be done in the next 5 years, when its orbit will be calculated more accurately.
