Natural satellites of the planets of the solar system. Moons of Mercury: real or hypothetical? Does Mercury have a satellite? Mercury moons names

The planet's orbit should be approximately between 5.3 and 7.3 degrees, the ascending node longitude was about 183 degrees, the eccentricity of the planet's orbit was "enormous", and the time it took for the planet to cross the solar disk was 4 hours 30 minutes. Le Verrier studied these observations and calculated the planet's orbit: the orbital period was 19 days 7 hours, the average distance from the Sun was 0.1427 AU, the inclination was 12°10", the ascending node was 12°59". The diameter was significantly smaller than that of Mercury and the mass was about 1/17 of its mass. This body was too small to explain the deviation of Mercury's orbit, but perhaps it is the largest of the asteroids in the intra-Mercurian asteroid belt? Le Verrier fell in love with this planet and named it Volcano.

In 1860 there was a total solar eclipse. Le Verrier mobilized all the French and some other astronomers to search for Vulcan, but no one found it. Le Verrier's interest was now revived by Wolff's suspicious "sun points", but it was not until shortly before his death in 1877 that some more detailed "evidence" was published. On April 4, 1875, German astronomer H. Weber saw a round spot on the Sun. According to the orbit calculated by Le Verrier, the planet should have crossed the Sun on April 3 of this year, and Wolf noted that his planet with a period of 38 days should also cross the Sun at about the same time. This "round dot" was also photographed in Greenwich and Madrid.

There was another period of excitement following the total solar eclipse of July 29, 1878, when two observers claimed to have seen a small luminous disk near the Sun, which could only be a small planet within the orbit of Mercury: J.C. Watson (Professor of Astronomy at the University of Michigan University) believed that he had discovered TWO planets within the orbit of Mercury! Lewis Swift (discoverer of comet Swift-Tuttle, which returned in 1992) also saw the "star" and determined that it was Vulcan, but it was in a different location than Watson's two "intramercurial" planets. In addition to this, neither Watson's nor Swift's Volcanoes were consistent with Le Verrier's or Lescarbault's.

After this, no one ever saw Vulcan again, despite the fact that searches for him were carried out during several total solar eclipses. And in 1916, Albert Einstein published his General Theory of Relativity, which explained the deviation in Mercury's motion without the help of an unknown inner planet. In May 1929, Erwin Freundlich from Potsdam photographed a total solar eclipse in Sumatra and later carefully studied the photographs, which turned out to contain a large number of images of stars. Six months later, these images were compared with new ones. And no unknown objects brighter than magnitude 9 were discovered near the Sun.

But what then did these people really see? Lescarbot had no reason to tell fictitious stories and even Le Verrier believed him. It is likely that Lescarbault saw a small asteroid passing very close to the Earth, just inside the Earth's orbit. At that time, such asteroids were not yet known, so Lescarbault assumed that he had seen an intra-Mercurian planet. Swift and Watson may have misidentified some stars in the short minutes of observing a total solar eclipse, believing that they saw Vulcan.

"Vulcan" came to life briefly in 1970-1971, when some researchers thought they had found several obscure objects close to the Sun during a total solar eclipse. These objects could be faint comets. Later, similar comets were discovered that passed close enough to the Sun to collide with it.

Moons of Mercury, 1974

After Friday's excitement, when it was calculated that the "object" was moving at a speed of 4 km/sec (a speed consistent with it being a satellite), JPL management was called in. Everyone began to worry about the press conference scheduled for Saturday at the latest. Should I tell you about the suspicious satellite? But the press already knew. Some newspapers - larger, more respectable ones - gave honest information; many others came up with exciting stories about Mercury's new moon.

What about “satellite”? It moved directly from Mercury and was finally identified as the hot star 31 Crateris (constellation Chalice). Where the initial radiation that was detected on approach to the planet came from remains unknown. This is how the story about the satellites of Mercury ended, but at the same time, this is how new chapters in astronomy began: as it turned out, strong ultraviolet radiation is not completely absorbed by the interstellar medium, as previously thought. The Gum Nebula was found to be a fairly strong source of extreme ultraviolet light with a wavelength of 540 angstroms, spreading 140 degrees across the night sky. Astronomers have discovered a new window through which to observe the heavens.

Nate, satellite of Venus, 1672-1892

Thus, the astronomical world was divided into two parts: some observers reported that they saw the satellite, while others claimed that they could not find it, despite all their efforts. In 1766, the director of the Vienna Observatory, Father Hell, published a treatise in which he stated that all observations of the satellite were optical illusions - the image of Venus is so bright that the light from it is reflected from the observer's eye and falls back inside the telescope, where it creates a second smaller image. The other side published works in which they proved that all the observations were real. Lambert (J.H. Lambert) from Germany published the orbital elements of the satellite in the Berlin Astronomical Yearbook for 1777: the average distance from the planet is 66.5 radii of Venus, the orbital period is 11 days 3 hours, the angle of inclination of the orbit to the ecliptic is 64 degrees. He hoped that the satellite could be seen during the transit of Venus across the disk of the Sun on June 1, 1777 (Obviously, Lambert made an error in calculating the orbital elements: 66.5 radii of Venus is almost the same as from our Moon to Earth, the mass of Venus is slightly less than Earth's mass. This fits very poorly with a period of 11 days, which is only slightly more than 1/3 of the Moon's orbital period.)

In 1768, Christian Horrebow from Copenhagen observed the satellite again. Three more attempts were made to find it, one of them by the greatest astronomer of all time, William Herschel. All these attempts to find the satellite failed. Much later, F. Schorr of Germany attempted to publish facts about the satellite in a book published in 1875.

In 1884, M. Hozeau, the first director of the Royal Observatory in Brussels, proposed a different hypothesis. Analyzing the available observations, Ozo concluded that this satellite of Venus approaches Venus approximately every 2.96 years or 1080 days. He suggested that this object is not a satellite of Venus, but a separate planet that revolves around the Sun in 283 days and finds itself in conjunction with Venus once every 1080 days. Ozo also named her Neith, after the mysterious Egyptian goddess from Sais.

Three years later, in 1887, Ozo was revived by the “satellite of Venus.” The Belgian Academy of Sciences published a large article where all the observations presented were examined in detail. Several observations of the satellite turned out to actually be stars that were visible in the neighborhood of Venus. Roedkier's observations "were verified" especially well - they matched the stars Orion, Taurus, 71 Orionis and Gemini! James Short actually saw a star fainter than magnitude 8. All the observations of Le Verrier and Montaigne could be explained in a similar way. Lambert's orbital calculations were refuted. The most recent observations of Horrebow, in 1768, were attributed to the star Libra.

Since the publication of this article, only one observation has been reported - by an observer who had previously tried to detect a satellite of Venus, but was unable to do so: on August 13, 1892, E.E. Barnard detected a 7th magnitude object near Venus. In the place that Barnard noted there are no stars and “Barnard’s eyes lit up with the notorious admiration.” We still don't know what he saw. Was it an unmapped asteroid? Or is it a short-lived nova that no one else has ever seen?

Second satellite of the Earth, from 1846 to the present day

In 1846, Frederic Petit, director of Toulouse, announced that the second satellite of the Earth had been discovered. It was spotted by two observers in Toulouse [Lebon and Dassier] and a third by Lariviere in Artenac in the early evening of March 21, 1846. According to Petit's calculations, its orbit was elliptical with a period of 2 hours 44 minutes 59 seconds, with an apogee at a distance of 3570 km above the Earth's surface, and a perigee only at 11.4 km! Le Verrier, who was also present at the report, objected that it was necessary to take into account air resistance, which no one had done at that time. Petit was constantly haunted by the idea of ​​a second satellite of the Earth and 15 years later he announced that he had made calculations of the movement of a small satellite of the Earth, which is the cause of some (then unexplained) features in the movement of our main Moon. Astronomers generally ignore such claims and the idea would have been forgotten if a young French writer, Jules Verne, had not read the summary. In J. Verne's novel From a Gun to the Moon, a small object is used to approach the capsule to travel through outer space, causing it to fly around the Moon rather than crash into it: “This,” said Barbicane, “is a simple , but a huge meteorite, held like a satellite by the gravity of the Earth."

“Is it possible?” exclaimed Michel Ardant, “Does the earth have two satellites?”

“Yes, my friend, it has two satellites, although it is usually believed that it has only one. But this second satellite is so small and its speed is so great that the inhabitants of the Earth cannot see it. Everyone was shocked when the French astronomer, Monsieur Petit was able to discover the existence of a second satellite and calculate its orbit. According to him, a complete revolution around the Earth takes three hours and twenty minutes... "

“Do all astronomers admit the existence of this satellite?” asked Nicole

“No,” replied Barbicane, “but if they, like us, met him, they would no longer doubt... But this gives us the opportunity to determine our position in space... the distance to him is known and we were, therefore, at a distance of 7480 km above the surface of the globe when they met the satellite." Jules Verne was read by millions of people, but until 1942 no one noticed the contradictions in this text:

1. A satellite at an altitude of 7480 km above the Earth's surface should have an orbital period of 4 hours 48 minutes, not 3 hours 20 minutes
2. Since it was visible through a window through which the Moon was also visible, and since both of them were approaching, it would have to be in retrograde motion. This is an important point that Jules Verne does not mention.
3. In any case, the satellite must be in eclipse (by the Earth) and therefore not visible. The metal projectile was supposed to remain in the shadow of the Earth for some time.

Nevertheless, Jules Vernovsky's second companion Petit (in French Petit - small) is known throughout the world. Amateur astronomers concluded that this was a good opportunity to achieve fame - whoever discovered this second satellite could write his name in the scientific chronicles. None of the large observatories have ever dealt with the problem of the second satellite of the Earth, or if they did, they kept it secret. German amateur astronomers were persecuted for what they called Kleinchen(“little bit”, “a little bit”) - of course they never found Kleinchen.

In addition to ephemeral companions, there are two more interesting possibilities. One of them is that the Moon has its own satellite. But, despite intensive searches, nothing was found (We add that, as is now known, the gravitational field of the Moon is very “uneven” or heterogeneous. This is enough for the rotation of the lunar satellites to be unstable - therefore the lunar satellites fall to the Moon after a very short interval time, several years or decades later). Another suggestion is that there may be Trojan moons, i.e. additional satellites in the same orbit as the Moon, orbiting 60 degrees ahead and/or behind it.

The existence of such “Trojan satellites” was first reported by the Polish astronomer Kordylewski from the Krakow Observatory. He began his search in 1951 visually using a good telescope. He expected to detect a fairly large body in lunar orbit at a distance of 60 degrees from the Moon. The results of the search were negative, but in 1956 his compatriot and colleague Wilkowski suggested that there might be many tiny bodies too small to be seen individually, but large enough to appear as a cloud of dust. In this case, it would be better to observe them without a telescope, i.e. with the naked eye! Using a telescope will "magnify them into non-existence." Dr. Kordilevsky agreed to try. A dark night with a clear sky and the Moon below the horizon was required.

In October 1956, Kordilevsky saw a clearly luminous object for the first time in one of two expected positions. It was not small, extending to about 2 degrees (i.e. almost 4 times larger than the Moon itself), and was very dim, at half the brightness of the notoriously difficult counterradiance (Gegenschein; counterradiance is the bright point in the zodiacal light in direction opposite to the Sun). In March and April 1961, Kordilevsky achieved success in photographing two clouds near the expected positions. They seemed to change in size, but this could also be due to changes in lighting. J. Roach discovered these satellite clouds in 1975 using OSO (Orbiting Solar Observatory). In 1990 they were photographed again, this time by Polish astronomer Winiarski, who found that they formed an object several degrees in diameter, deviated by 10 degrees from the Trojan point and that they were redder than the zodiacal light.

So the century-long search for the second satellite of the Earth seems to have come to success, after all the efforts. Even though this "second satellite" turned out to be completely different from what anyone had ever imagined. They are very difficult to detect and differ from the zodiacal light, in particular from the counterradiance.

But people still assume the existence of an additional natural satellite of the Earth. Between 1966 and 1969, John Bargby, an American scientist, claimed to have observed at least 10 small natural satellites of the Earth visible only through a telescope. Bargby found elliptical orbits for all these objects: eccentricity 0.498, semimajor axis 14065 km, with perigee and apogee at altitudes of 680 and 14700 km, respectively. Bargby believed they were parts of a larger body that collapsed in December 1955. He justified the existence of most of his putative satellites by the disturbances they cause in the movements of artificial satellites. Bargby used data on artificial satellites from the Goddard Satellite Situation Report, unaware that the values ​​in these publications are approximate and can sometimes contain large errors and therefore cannot be used for accurate scientific calculations and analysis. Moreover, from Bargby's own observations, it can be concluded that although at perigee these satellites should be objects of first magnitude and should be clearly visible to the naked eye, no one has seen them like that.

In 1997, Paul Wiegert and others discovered that asteroid 3753 has a very strange orbit and could be regarded as a satellite of the Earth, although, of course, it does not orbit the Earth directly.

Moons of Mars, 1610, 1643, 1727, 1747, 1750 and from 1877 to the present time

In 1643, Capuchin monk Anton Maria Shyrl claimed to have actually seen the moons of Mars. We now know that this was impossible with the telescopes of that time - Shirl was probably mistaken when he saw a star near Mars.

In 1727, Jonathan Swift, in his work Gulliver's Travels, wrote about two small satellites orbiting Mars, known to Laputan astronomers. Their orbital periods were 10 and 21.5 hours. These “satellites” were borrowed by Voltaire in 1750 in his novel “Micromegas”, which told about a giant from Sirius who visited our solar system.

In 1747, the German captain Kindermann claimed to have seen a satellite (only one!) of Mars on July 10, 1744. Kindermann reported that the orbital period of this Martian satellite is 59 hours 50 minutes and 6 seconds (!)

In 1877, Asaph Hall finally discovered Phobos and Deimos, two small moons of Mars. Their orbital periods are respectively 7 hours 39 minutes and 30 hours 18 minutes, quite close to the values ​​​​predicted by Jonathan Swift 150 years earlier!

14th Satellite of Jupiter , 1975-1980

Saturn's ninth and tenth moons , 1861, 1905-1960, 1966-1980

In 1905, Pickering, however, discovered a tenth satellite, which he called Themis. According to Pickering's data, it orbited Saturn between Titan and Hyperion in a highly inclined orbit: average distance from Saturn - 1,460,000 km, orbital period 20.85 days, eccentricity 0.23, inclination angle 39 degrees. Themis was never seen again, but was nonetheless reported in almanacs and astronomy books again and again in the 1950s and 1960s.

In 1966, A. Dollfus discovered another new satellite of Saturn. Which was named Janus. It orbits Saturn, just on the outside of its rings. It was so faint and close to the rings that the only chance to see it was when Saturn's rings were visible edge-on. This happened in 1966. Janus is now Saturn's tenth moon.

In 1980, when Saturn's rings were again visible edge-on. A flurry of observations has revealed many new satellites of Saturn near its rings. Another moon was discovered near Janus, named Epimetheus. The orbits of these satellites are very close to each other. A particularly interesting property of this pair of satellites is that they regularly “exchange” orbits! It turned out that Janus, discovered in 1966, was in fact an observable object consisting of both of these co-orbiting satellites. This is why the “tenth moon of Saturn,” discovered in 1966, actually turned out to be two different moons! The Voyager 1 and Voyager 2 spacecraft, which subsequently visited Saturn, confirmed this.

Six Moons of Uranus , 1787

Planet X , 1841-1992

(Inspired by this success, Le Verrier took up the problem of the deviation of the orbit of Mercury and proposed the existence of an intra-Mercurian planet Vulcan, which, as it turned out, does not exist.)

On September 30, 1846, a week after the discovery of Neptune, Le Verrier stated that there might be another unknown planet there. On October 10, Neptune's large moon Triton was discovered, with which it was easy to measure Neptune's mass with great accuracy. It turned out to be 2% greater than expected from calculations of its interaction with Uranus. It looked as if the deviations in Uranus' motion were actually caused by two planets, especially since Neptune's actual orbit was markedly different from that predicted by Adams and Le Verrier.

In 1850, Ferguson observed the movements of the minor planet Hygeia. One of the readers of Ferguson's report was Hind, who tested the guide stars that Ferguson was using. Hind was unable to find one of Ferguson's main stars. Maury of the Naval Observatory also could not find this star. For several years, it was thought that this was an observation of another planet, but in 1879 another explanation was proposed: Ferguson had made an error in recording his observations - when this error was corrected, another star was well suited to be the "lost guide star."

The first serious attempt to find trans-Neptunian planets was made by David Todd in 1877. He used the "graphical method" and, despite ill-defined deviations in the motion of Uranus, determined the elements for the trans-Neptunian planets: average distance 52 AU, period 375 years, magnitude weaker than 13. Their longitude for the period 1877-84 years was given as 170 degrees with an error of 10 degrees. The orbital inclination angle was 1.40 degrees and the longitude of the ascending node was 103 degrees.

In 1879, Camille Flammarion hinted at the existence of a planet beyond Neptune: he noted that the aphelions of periodic comets tend to cluster around the orbit of large planets. Jupiter has the largest number of such comets, Saturn, Uranus and Neptune also have a number of them. Flammarion discovered two comets - 1862 III with a period of 120 years and an aphelion of 47.6 AU. and 1889 II with a rather long period and aphelion of 49.8 AU. Flammarion suggested that the hypothetical planet was probably moving at a distance of 45 AU.

A year later, in 1880, Professor Forbes published memoirs concerning the aphelion of comets and their relationship with planetary orbits. By the beginning of 1900, 5 comets with aphelion were known on the other side of Neptune's orbit, and then Forbes suggested one trans-Neptunian planet moving at a distance of about 100 AU. and another at a distance of 300 AU, with periods of 1000 and 5000 years.

Over the next five years, several astronomers/mathematicians published their own ideas about what might be found in the outer solar system. Gaillot of the Paris Observatory suggested the existence of two trans-Neptunian planets at a distance of 45 and 60 AU, respectively. Thomas Jefferson predicted three trans-Neptunian planets: "Ocean" at 41.25 AU. with a period of 272 years, "Trans-Ocean" at 56 AU. with a period of 420 years, and finally another planet at a distance of 72 AU. with a period of 610 years. Dr. Theodor Grigull of Münster (Germany), proposed in 1902 a planet the size of Uranus at 50 AU. and with a period of 360 years, which he called "Hades". Grigullus based his work mainly on the orbits of comets whose aphelion orbits lay beyond the orbit of Neptune. There they could experience the gravitational influence of the body, which caused a noticeable deviation in the movement of Uranus. In 1921, Grigulle revised the value of the orbital period of Hades, since a value of 310-330 years was more suitable to explain the observed deviations.

In 1900, Hans-Emil Lau of Copenhagen published the orbital elements of two trans-Neptunian planets at distances of 46.6 and 70.7 AU, with masses 9 and 47.2 times Earth's and brilliances of about 10-11 magnitude. The longitude of these hypothetical planets in 1900 should have been 274 and 343 degrees, but with a very large error for both planets (up to 180 degrees).

In 1901, Gabriel Dalle came to the conclusion of the existence of a hypothetical planet at a distance of 47 AU. with a magnitude of about 9.5-10.5 magnitude and a longitude of 358 degrees for the epoch of 1900. In the same year, Theodor Grigull derived a longitude for the trans-Neptunian planet that was less than 6 degrees different from the value for Dalle's planet, and later the difference decreased to 2.5 degrees. This planet was assumed to be at a distance of 50.6 AU.

In 1904, Thomas Jefferson proposed the existence of three trans-Neptunian planets with semi-axes 42.25, 56 and 72 AU. The innermost planet had a period of 272.2 years and a longitude of 200 degrees in 1904. Russian general Alexander Garnovsky proposed four hypothetical planets, but was unable to substantiate some of the details regarding their positions and movements.

Two particularly elaborate predictions about trans-Neptunian planets were of American origin: Pickering's Quest for the Planets Beyond Neptune (Annals Astron. Obs. Harvard Coll, vol LXI part II, 1909) and Memoirs of the Trans-Neptunian Planets. Percival Lowell (Lynn, Mass 1915). They were interested in the same question, but used different approximations and obtained different results.

Pickering used graphical analysis and believed that "Planet O" was at a distance of 51.9 AU. with a period of 373.5 years, a mass twice the mass of the Earth and a magnitude of 11.5-14. Pickering, over the next 24 years, proposed eight other trans-Neptunian planets. Pickering's results were the reason for Galiot to correct the distances to his two trans-Neptunian planets to 44 and 66 AU. and changes in their masses by 5 and 24 Earth masses, respectively.

In total, between 1908 and 1932, Pickering proposed seven hypothetical planets - O, P, Q, R, S, T and U. The final values ​​of the orbital elements for planets O and P identified bodies completely different from the original ones. Thus, the planets predicted by him became nine, which is undoubtedly a record. Most of Pickering's predictions aroused only short-term interest, like some kind of curiosity. In 1911, Pickering proposed that Planet Q had a mass of 20,000 Earth masses, making it 63 times more massive than Jupiter, or about 1/6 the mass of the Sun, closer to a minimum-mass star than a planet. In addition, for this planet (Q), Pickering predicted a very elliptical orbit.

In subsequent years, only planet P seriously occupied his attention. In 1928, he reduced the distance for planet P from 123 to 67.7 AU, and its period from 1400 to 556.6 years. He estimated the planet's mass to be 20 Earth masses and its brightness to be about magnitude 11. In 1931, after the discovery of Pluto, he changed the orbital parameters of planet P: distance 75.5 AU, period 656 years, mass 50 Earth masses, eccentricity 0.265, orbital inclination 37 degrees, which approaches the values ​​of the 1911 orbit. He proposed Planet S in 1928, and estimated its orbital elements in 1931: the distance from the Sun is 48.3 AU. (which is close to the Lowell value of Planet X - 47.5 AU), period 336 years, mass 5 Earth masses, magnitude - 15 m. In 1929, Pickering proposed planet U, at a distance of 5.79 AU, with a period of 13.93 years, within the orbit of Jupiter. Its mass was about 0.045 Earth masses, eccentricity 0.26. The last planet Pickering proposed was Planet T, which he predicted in 1931: semi-axis 32.8 AU, period 188 years.

Elements of the orbit of planet O in different years:

Year Average Period Mass Magnitude Node Inclination Longitude distance (years) (Earth mass) orbit 1908 51.9 373.5 2 11.5-13.4 105.13 1919 55.1 409 15 100 15 1928 35.23 209.2 0.5 12 Percival Lowell, best known as the Mars canals promoter, built a private observatory laboratory in Flagstaff, State Arizona. He named his hypothetical planet Planet X and made several attempts to find it, but to no avail. Lowell's first attempts to find Planet X occurred at the end of 1909, and in 1913 he made a second attempt to find it, based on new predictions for the parameters of Planet X: for the epoch 1850-01-01, the average longitude was 11.67 degrees, the perigee longitude 186 , eccentricity 0.228, average distance 47.5 AU from the Sun, longitude of the ascending node 110.99 degrees, orbital inclination angle 7.30 degrees, planet mass 1/21000 of the mass of the Sun. Lowell and other astronomers searched in vain for Planet X from 1913-1915. In 1915, Lowell published his theoretical results on Planet X. Ironically, also in 1915, Lowell Observatory recorded two fuzzy images of Pluto, although they were not recognized as images of the planet until its "official" discovery in 1930 year. Lowell's failure to find Planet X was his greatest disappointment. In the last two years of his life, he no longer spent much time searching for Planet X. Lowell died in 1916. From the approximately 1000 image plates he obtained during the second search attempt, 515 asteroids, 700 different stars and 2 images of Pluto were subsequently discovered!

A third attempt to find Planet X began in April 1927. No progress was made during 1927-1928. In December 1929, a young farmer and amateur astronomer from Kansas, Clyde Tombaugh, was invited to conduct the search. Tombaugh began his work in April 1929. On January 23 and 29 of this year, Tombaugh photographed several photographic plates on which he found Pluto, while examining them on February 18. By that time, Tombaugh had already examined hundreds of pairs of such plates with millions of stars. The search for Planet X has come to an end.

Is it towards the end? The new planet, later named Pluto, turned out to be disappointingly small, with a mass of perhaps one Earth's mass, and perhaps only 1/10 of the Earth's mass or less (in 1979, when Pluto's moon Charon was discovered, it was found that The mass of the Pluto-Charon pair is about 1/400 of the mass of the Earth!). Planet X, if it is the one causing the disturbances in Uranus's orbit, must be much larger than this! Tombaugh continued his search for another 13 years and explored the sky from the north celestial pole to the south declination of 50 degrees, reaching in his searches up to 16-17, and sometimes even 18 magnitude. Tombaugh examined approximately 90 million images of nearly 30 million stars across more than 30,000 square degrees of the celestial sphere. He discovered one new globular cluster, 5 new open star clusters, one supercluster consisting of 1800 galaxies and several small clusters of galaxies, one new comet, about 775 new asteroids - but not a single new planet except Pluto. Tombaugh concluded that there were no unknown planets brighter than magnitude 16.5 - only planets in near-polar orbits or located close to the south celestial pole could escape his research and be discovered. He hoped to discover a Neptune-sized planet at seven times the distance of Pluto, or a Pluto-sized planet at 60 AU.

Giving Pluto his name makes up a separate story. The first proposed names for the new planet were: Atlas, Zymal, Artemis, Perseus, Vulcan, Tantalus, Idana, Cronus. The New York Times suggested the name Minerva; reporters suggested Osiris, Bacchus, Apollo, Erebus. Lowell's widow suggested naming the planet Zeus, but later changed her mind to Constance. Many suggested naming it after Lowell. Staff at the Flagstaff Observatory, where Pluto was discovered, suggested the names Cronus, Minerva, and Pluto. A few months later, the planet was officially named Pluto. The name Pluto was originally suggested by Venetia Burney, an eleven-year-old schoolgirl from Oxford, England.

The very first orbital parameters calculated for Pluto gave an eccentricity of 0.909 and a period of 3000 years! This casts some doubt on whether this was the same planet we know today or not. However, several months later, more accurate orbital elements were obtained. Below is a comparison of the orbital elements of Lowell's Planet X, Pickering's Planet O, and Pluto:

Planet X Planet O Pluto (Lowell) (Pickering) a (average distance) 43.0 55.1 39.5 e (eccentricity) 0.202 0.31 0.248 i (inclination angle) 10 15 17.1 N (longitude of ascending node) [not predicted] 100 109.4 W (longitude perihelion) 204.9 280.1 223.4 T (perihelion date) Feb. 1991 Jan 2129 Sep. 1989 u (annual motion) 1.2411 0.880 1.451 P (period, years) 282 409.1 248 T (date of passage of peri.) 1991.2 2129.1 1989.8 E (longitude 1930.0) 102.7 102.6 108.5 m (mass, Earth=1) 6 .6 2.0 0.002 M (stellar value) 12-13 15 15

Pluto's mass has been very difficult to determine. Several values ​​have been proposed at various times - the question remained open until James W. Christy discovered Pluto's moon Charon in June 1978 - at that time it was believed that Pluto had a mass equal to only 20% of the mass our Moon! This made Pluto completely unsuited to exert a significant gravitational influence on Uranus and Neptune. Pluto could not be Lowell's Planet X - the planet found was not the one they were looking for. What seemed to be a triumph of celestial mechanics turned out to be a fluke, or rather the result of Clyde Tombaugh's careful search.

Pluto mass:

Crommelin 1930: 0.11 (Earth mass) Nicholson 1931: 0.94 Wylie 1942: 0.91 Brouwer 1949: 0.8-0.9 Kuiper 1950: 0.10 1965:<0.14 (по затемнениям слабых звезд Плутоном) Сидельманн (Seidelmann) 1968: 0.14 Сидельманн (Seidelmann) 1971: 0.11 Кройкшранк (Cruikshank) 1976: 0.002 Кристи (Christy) 1978: 0.002 (открыватель Харона)

Another short-lived trans-Neptunian planet was reported on April 22, 1930 by R.M. Stewart of Ottawa, Canada, discovered in photographs taken in 1924. Crommelin calculated its orbit (distance 39.82 AU, ascending node 280.49 degrees, orbital inclination 49.7 degrees!). Tombaugh began searching for the "Ottawa object" but found nothing. Other search attempts were made, but also without results.

Meanwhile, Pickering continued to predict new planets (see above). Other astronomers have also predicted new planets based on theoretical considerations (Lowell himself had already predicted a second trans-Neptunian planet at a distance of about 75 AU). In 1946, Francis M.E. Sevin proposed the existence of a trans-Pluto planet at a distance of 78 AU. He reached this conclusion based on a strange empirical method in which he divided the planets and the asteroid Hidalgo into two groups of internal and external bodies:

Group I: Mercury Venus Earth Mars Asteroids Jupiter Group II: ? Pluto Neptune Uranus Saturn Hidalgo Then he added up the logarithms of the periods of each pair of planets, arriving at a roughly constant sum of about 7.34. Assuming that the same amount would be given by a pair from Mercury and trans-Pluto, he obtained a period of about 677 years for “Transpluto”. Sevin later calculated the full set of Transpluto orbital elements: distance 77.8 AU, period 685.8 years, eccentricity 0.3, mass 11.6 Earth masses. His prediction aroused little interest among astronomers.

In 1950, K. Schutte of Munich used data for eight periodic comets to predict a trans-Pluto planet at a distance of 77 AU. Four years later, H.H. Kitzinger of Karlsruhe, using the same comets, expanded and refined the previous work - he got a planet at a distance of 65 AU, with a period of 523.5 years, an orbital inclination of 56 degrees and an estimate magnitude about 11. In 1957, Kitzinger revised this problem and obtained new orbital elements: distance 75.1 AU, period 650 years, inclination angle 40 degrees, magnitude about 10. After unsuccessful photographic searches, he repeated his calculations again, in 1959 , it turned out that the average distance to the planet is 77 AU, the period is 675.7 years, the inclination angle is 38 degrees, the eccentricity is 0.07, i.e. the planet is not the same as Sevin’s “Transpluto”, but is more similar in some respects to Pickering’s last Planet P. However, no such planet has been discovered.

Halley's Comet has also been used as a detection "probe" for trans-Plutonian planets. In 1942, R.S. Richardson discovered that an Earth-sized planet was located at a distance of 36.2 AU. from the Sun or 1 AU from the aphelion of Comet Halley, should delay the moment of passage of its perihelion, which was in good agreement with observations. Planet at a distance of 35.3 AU and with a mass of 0.1 Earth should give similar effects. In 1972, Brady predicted a planet at a distance of 59.9 AU, with a period of 464 years, an eccentricity of 0.07, an inclination angle of 120 degrees (i.e., in a retrograde orbit), with a magnitude of about 13-14, about the size of Saturn. Such a trans-Plutonian planet would have slowed down Halley's Comet at its 1456th perihelion passage. This giant trans-Pluto planet was also searched for, but was not found.

Tom van Flandern studied the positions of Uranus and Neptune in the 1970s. The calculated orbit of Neptune coincided with observations for only a few years, and then began to deviate to the side. Uranus' orbit matched observations during one orbital period, but not during the previous orbit. In 1976, Tom van Flandern became convinced that it was caused by a tenth planet. After the discovery of Charon in 1978, which showed that Pluto's mass was actually much smaller than thought, van Flandern convinced his USNO colleague Robert S. Harrington that a tenth planet existed. They began to collaborate in the study of Neptune's satellite system. Soon their views diverged. Van Flandern believed that the tenth planet formed beyond the orbit of Neptune, while Harrington believed that it originated in the orbits of Uranus and Neptune. Van Flandern believed that more data was needed, such as the refined mass of Neptune obtained from Voyager 2. Harrington began searching for the planet with superhuman zeal - starting in 1979, he still had not found any planet until 1987. Van Flandern and Harrington suggested that the tenth planet may be near aphelion in a highly elliptical orbit. If the planet is dark, it may be no brighter than magnitude 16-17 (this assumption was put forward by van Flandern).

In 1987, Whitmire and Matese predicted a tenth planet at 80 AU. with a period of 700 years and an orbital inclination angle of about 45 degrees, as an alternative to the “Nemesis” hypothesis. However, according to Eugene M. Shoemaker, this planet could not be the cause of the meteor shower, the existence of which was suggested by Whitemere and Mathes (see below).

In 1987, John Anderson of JPL tested the movements of the Pioneer 10 and Pioneer 11 spacecraft to see if their movements would be deflected by gravitational forces from unknown bodies. Nothing was discovered - from this Anderson concluded that a tenth planet most likely exists! JPL excluded observations of Uranus before 1910 from its ephemeris calculations, while Anderson used them as well. Anderson concluded that the tenth planet must have a highly eccentric orbit, taking it too far from the Sun to be detected now, but periodically bringing it close enough that it could leave its "exciting signature on the paths of other planets." He also suggested that its mass is equal to five times that of the Earth, its orbital period is about 700-1000 years, and its orbit is highly inclined. Its influence on the inner planets will not be detected again until at least 2600. Anderson hoped that Voyagers would help determine the position of this planet.

JPL's Conley Powell also analyzed planetary motion. He also found that observations of Uranus matched calculations after 1910 much better than before. Powell suggested that the discrepancy was caused by a planet with a mass of 2.9 Earth masses at a distance of 60.8 AU from the Sun, with a period of 494 years, an inclination angle of 8.3 degrees and a small eccentricity. Powell suggested that its period is approximately equal to two periods of Pluto and three periods of Neptune. He assumed that the planet he discovered had an orbit stabilized by mutual resonance with its nearest neighbors, despite their great distance from each other. The solution indicated that the planet was in the constellation Gemini and was also brighter than Pluto when it was discovered. The search for Powell's planet began in 1987 at the Lowell Observatory - but nothing was found. Powell repeated his calculations and obtained the following elements: mass - 0.87 Earth masses, distance 39.8 AU, period 251 years, eccentricity 0.26, i.e. the orbit is very similar to the orbit of Pluto! Accordingly, the new Powell planet should be located in the constellation Leo and have a brightness of about 12 magnitude. However, Powell himself thinks that these data are too premature to search for the planet and need additional verification.

Even if trans-Pluto planets are never found, the outer parts of the solar system will still focus the attention of researchers. We have already mentioned the asteroid Hidalgo, which moves in an unstable orbit between Jupiter and Saturn. In 1977-1984, Charles Kowal introduced a new systematic search program for undiscovered solar system objects using the Palomar Observatory's 48-inch Schmidt camera. In October 1987, he discovered the asteroid 1977UB, later named Chiron, moving at an average distance of 13.7 AU, with a period of 50.7 years, an eccentricity of 0.3786, an inclination angle of 6.923 degrees, and a diameter of about 50 km. During these searches, Kowal also discovered 5 comets and 15 asteroids, (including Chiron), the most distant asteroid ever discovered. Koval also rediscovered 4 lost comets and one lost asteroid. He did not find a tenth planet and concluded that there was no unknown planet brighter than magnitude 20 within three degrees of the ecliptic.

In the first announcement of the discovery of Chiron, it was called the “tenth planet”, but then it was immediately designated as an asteroid. However, Koval suspected that this body might be very similar to a comet, and later it even acquired a short comet-like tail! In 1995, Chiron was also classified as a comet - of course, as the largest comet we know anything about.

In 1992, another distant asteroid was discovered: Pholus. An asteroid beyond Pluto's orbit was later discovered in 1992, followed by five more trans-Pluto asteroids discovered in 1993, and finally over ten more in 1994!

However, the Pioneer 10 and 11, Voyager 1 and 2 spacecraft traversed the outer solar system, and could also be used as "probes" to detect unknown gravitational influences, possibly caused by unknown planets - but nothing was detected. The Voyagers also established more accurate masses for the outer planets; when these updated data were used to numerically integrate the motions of the solar system, all disagreements regarding the positions of the outer planets finally disappeared. It seems that the search for "Planet X" has finally come to an end. There was no "Planet X" (Pluto doesn't really count), but instead an asteroid belt beyond the orbits of Neptune and Pluto was discovered! Asteroids beyond Jupiter's orbit that were discovered in August 1993 are presented below:

Asteroid a e Inc. Sunrise Arg perig. Avg. Period Name a.e. hail hail hail hail year. 944 5.79853 .658236 42.5914 21.6567 56.8478 60.1911 14.0 Hidalgo 2060 13.74883 .384822 6.9275 209.3969 339.2884 342.1686 51.0 Chiron 5145 20.44311 .575008 24.6871 119.3877 354.9451 7.1792 92.4 Pholus 5335 11.89073 .866990 61.8583 314.1316 191.3015 23.3556 41.0 Damocles 1992QB1 43.82934 .087611 2.2128 359.4129 44.0135 324.1086 290 1993FW 43.9311 .04066 7.745 187.914 359.501 0.4259 291 Epoch: 1993-08-01.0 TT In November 1994, the following trans-Neptunian asteroids were discovered:
Object a e tilt R Sv.v. Diam. The Discoverer a.e. was discovered. hail km Date 1992 QB1 43.9 0.070 2.2 22.8 283 1992 Aug Jewitt & Luu 1993 FW 43.9 0.047 7.7 22.8 286 1993 Mar Jewitt & Luu 1993 RO 39.3 0.198 3.7 23.2 139 1 993 Sep Jewitt & Luu 1993 RP 39.3 0.114 2.6 24.5 96 1993 Sep Jewitt & Luu 1993 SB 39.4 0.321 1.9 22.7 188 1993 Sep Williams et al. 1993 SC 39.5 0.185 5.2 21.7 319 1993 Sep Williams et al. 1994 ES2 45.3 0.012 1.0 24.3 159 1994 Mar Jewitt & Luu 1994 EV3 43.1 0.043 1.6 23.3 267 1994 Mar Jewitt & Luu 1994 GV9 42.2 0.000 0.1 23.1 264 1994 Apr Jewitt & Luu 1994 JQ1 43.3 0.000 3.8 22.4 382 1994 May Irwin et al. 1994 JR1 39.4 0.118 3.8 22.9 238 1994 May Irwin et al. 1994 JS 39.4 0.081 14.6 22.4 263 1994 May Luu & Jewitt 1994 JV 39.5 0.125 16.5 22.4 254 1994 May Jewitt & Luu 1994 TB 31.7 0.000 10.2 21.5 258 199 Oct 4 Jewitt & Chen 1994 TG 42.3 0.000 6.8 23.0 232 Oct 1994 Chen et al. 1994 TG2 41.5 0.000 3.9 24.0 141 1994 Oct Hainaut 1994 TH 40.9 0.000 16.1 23.0 217 1994 Oct Jewitt et al. 1994 VK8 43.5 0.000 1.4 22.5 273 1994 Nov Fitzwilliams et al. The diameter is given in km (it is calculated from stellar magnitudes and the most probable albedo and is given for a large number of objects) Trans-Neptunian bodies are divided into two groups. One group, consisting of Pluto, 1993 SC, 1993 SB and 1993 RO, has eccentric orbits and is in a 3:2 resonance with Neptune. The second group includes 1992 QB1 and 1993 FW, which are much further away and have low eccentricity.

Nemesis, companion star of the Sun, 1983 to present

This would mean that once every 30 million years, this hypothetical companion star of the Sun should pass through the Oort cloud (a hypothetical cloud of proto-comets that is at a very great distance from the Sun). During this passage, the proto-comets in the Oort cloud around this star will be churned up. And in a few tens of thousands of years, here on Earth we might notice a catastrophic increase in the number of comets crossing the inner parts of the Solar System. If the number of comets increases very much, then the Earth risks colliding with the nucleus of one of them.

When studying the geological history of the Earth, it was discovered that approximately once every 30 million years a mass extinction of living creatures occurred on Earth. The most famous of these is, of course, the extinction of the dinosaurs about 65 million years ago. According to this hypothesis, approximately 15 million years from today, the time will come for the next mass extinction of life.

The Sun's "deadly companion" hypothesis was proposed in 1985 by Daniel. Daniel P. Whitmire and John J. Matese from South Louisiana University (USA). This star even got a name: Nemesis. The only unpleasant aspect of this hypothesis is that there is no indication at all of the existence of a companion star near the Sun. It needs to be very bright or massive, even a star much smaller and dimmer than the Sun and it would be noticed, even a brown or black dwarf (a planet-like body is not massive enough to begin the process of “hydrogen burning” like a star). It is quite possible that this star already exists in one of the catalogs of faint stars and no features have been discovered for it (namely, the huge apparent motion of this star relative to more distant background stars, i.e. its small parallax). If the existence of this star were proven, few would doubt that this is the primary cause of the periodic extinction of species on Earth.

But this hypothesis has all the prerequisites of a myth. If an anthropologist of a previous generation had heard such a story from his informants, he would undoubtedly have used words such as “primitive” or “pre-scientific” when he finished writing it down in his next volume of academic works. Listen, for example, to the following story: There is another Sun in the sky, the Demon Sun, which we do not see. Many years ago, even before the great time of the forefathers, the Demon Sun attacked our Sun. Comets fell and a terrible winter enveloped the Earth. Almost all life was destroyed. The Sun Demon had attacked many times before. And he will attack again. That's why some scientists, when they first heard it, thought that the Nemesis theory was just a joke - an invisible Sun attacking the Earth along with comets, it sounds like a delusion or a myth. For this reason, many have joked skeptically: we are always in danger of deceiving ourselves. But even if this theory does not have a strong basis, it is still serious and quite valid, since its basic idea can be tested: you find a star and check its properties.

However, since the IRAS satellite surveyed the entire sky in the infrared range and did not find Nemesis radiation in it, its existence has become very unlikely.

Links

Willy Ley: "Watcher's of the skies", The Viking Press NY, 1963,1966,1969

William Graves Hoyt: "Planet X and Pluto", The University of Arizona Press 1980, ISBN 0-8165-0684-1, 0-8165-0664-7 pbk.

Carl Sagan, Ann Druyan: "Comet", Michael Joseph Ltd, 1985, ISBN 0-7181-2631-9

Mark Littman: "Planets Beyond - discovering the outer solar system", John Wiley 1988, ISBN 0-471-61128-X

Tom van Flandern: "Dark Matter, Missing Planets & New Comets. Paradoxes resolved, origins illuminated", North Atlantic Books 1993, ISBN 1-55643-155-4

Joseph Ashbrook: "The many moons of Dr Waltemath", Sky and Telescope, Vol 28, Oct 1964, p 218, also on pages 97-99 of "The Astronomical Scrapbook" by Joseph Ashbrook, SKy Publ. Corp. 1984, ISBN 0-933346-24-7

Delphine Jay: "The Lilith Ephemeris", American Federation of Astrologers 1983, ISBN 0-86690-255-4

William R. Corliss: "Mysterious Universe: A handbook of astronomical anomalies", Sourcebook Project 1979, ISBN 0-915554-05-4, p 45-71 "The intramercurial planet", p 82-84 "Mercury"s moon that wasn't "t", p 136-143 "Neith, the lost satellite of Venus", p 146-157 "Other moons of the Earth", p 423-427 "The Moons of Mars", p 464 "A ring around Jupiter?" , p 500-526 "Enigmatic objects"

- planets - small bodies

The interplanetary probe Messenger was launched in early August 2004 from Cape Canaveral by American specialists. The name of the device is translated from English as “messenger”. This name perfectly reflects the mission of the probe, which was to reach the planet Mercury, distant from Earth, and collect data of interest to scientists. The unique flight of the spacecraft attracted the attention of many researchers, who were eagerly awaiting the first results from Mercury.

The journey of the Earth's messenger lasted almost seven years. During this time, the device flew more than 7 billion kilometers, as it had to perform a number of gravitational maneuvers, slipping between the fields of the Earth, Venus and Mercury itself. The voyage of an artificial vehicle turned out to be one of the most difficult missions in the history of space exploration.

In March 2011, several estimated approaches of the probe to Mercury took place, during which Messenger adjusted its orbit and turned on a fuel-saving program. When the maneuvers were completed, the probe actually turned out to be an artificial satellite of Mercury, rotating around the planet in an optimal orbit. The messenger from Earth began to carry out the main part of his mission.

Artificial satellite of Mercury on space watch

The Messenger probe operated as an artificial satellite of Mercury until mid-March 2013, orbiting the surface at an altitude of approximately 200 km. During its stay near the planet, the probe collected and transmitted to Earth a lot of useful information. Many of the data were so unusual that they changed the usual understanding of scientists about the features of Mercury.

Today it has become known that in ancient times there were volcanoes on Mercury, and the geological composition of the planet is complex and diverse. Mercury's core is made of molten metal. There is also a magnetic field there, which, however, behaves quite strangely. It is still difficult for specialists to draw accurate conclusions about the presence of an atmosphere on the planet and its possible composition. This will require additional research.

An additional bonus for scientists was a unique “photo portrait” of the Solar System, which the first artificial satellite of Mercury managed to take. The photo shows almost all the planets in the solar system, with the exception of Uranus and Neptune. Having completed its scientific mission in 2013, the NASA probe made an invaluable contribution to the development of ideas about space objects closest to Earth.

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