The planet Mercury is the smallest planet terrestrial group, the first from the Sun, the innermost and smallest planet in the solar system, revolving around the Sun in 88 days. The apparent magnitude of Mercury ranges from -2.0 to 5.5, but it is not easy to see due to its very small angular distance from the sun. Its radius is only 2439.7 ± 1.0 km, which is less than the radius of the moon Ganymede and the moon Titan. The mass of the planet is 3.3x1023 kg. The average density of the planet Mercury is quite high - 5.43 g / cm³, which is only slightly less density Earth. Considering that the Earth is larger in size, the value of the density of Mercury indicates an increased content of metals in its bowels. The free fall acceleration on Mercury is 3.70 m/s². Second space velocity- 4.3 km / s. The planet can never be seen in the dark night sky. The optimal time for observing the planet is the morning or evening periods of the maximum distance of Mercury from the Sun in the sky, which occur several times a year. Relatively little is known about the planet. In 1974-1975, only 40-45% of the surface was photographed. In January 2008, the MESSENGER interplanetary station flew past Mercury, which will enter orbit around the planet in 2011.

In its physical characteristics, Mercury resembles the Moon. It is dotted with many craters, the largest of which is named after the great German composer Beethoven, its diameter is 625 km. The planet has no natural satellites, but there is a very rarefied atmosphere. The planet has a large iron core, which is the source of magnetic field and in their totality making up 0.1 of the earth. Mercury's core makes up 70% of the planet's total volume. The temperature on the surface of Mercury ranges from 90 to 700 K (-180, 430 °C). Despite the smaller radius, the planet Mercury still surpasses in mass such satellites of the giant planets as Ganymede and Titan. Mercury moves around in a rather highly elongated elliptical orbit at an average distance of 57.91 million km. The inclination of the orbit to the plane of the ecliptic is 7 degrees. Mercury spends 87.97 days per orbit. average speed the motion of the planet in an orbit of 48 km/s. In 2007, Jean-Luc Margot's group summarized five years of radar observations of Mercury, during which they noticed variations in the planet's rotation that were too large for a model with a solid core.

The proximity to the Sun and the rather slow rotation of the planet, as well as the absence of an atmosphere, lead to the fact that Mercury experiences the sharpest temperature drops in. The average temperature of its daytime surface is 623 K, the nighttime temperature is only 103 K. The minimum temperature on Mercury is 90 K, and the maximum reached at noon at "hot longitudes" is 700 K. Despite such conditions, in recent times there were suggestions that ice could exist on the surface of Mercury. Radar studies of the polar regions of the planet have shown the presence of a highly reflective substance there, the most likely candidate for which is ordinary water ice. Entering the surface of Mercury when comets hit it, the water evaporates and travels around the planet until it freezes in the polar regions at the bottom of deep craters, where the Sun never looks, and where ice can remain almost indefinitely.

On the surface of the planet, smooth rounded plains were discovered, which received the name of basins by their resemblance to the lunar "seas". The largest of them, Kaloris, has a diameter of 1300 km (the ocean of Storms on the Moon is 1800 km). The appearance of valleys is explained by intense volcanic activity, which coincided in time with the formation of the planet's surface. The planet Mercury is partially strewn with mountains, the height of the highest reaches 2–4 km. In some regions of the planet, valleys and craterless plains are visible on the surface. On Mercury, there is also an unusual detail of the relief - the scarp. This is a 2–3 km high protrusion separating two surface regions. It is believed that the scarps formed as shifts during the early compression of the planet.

The oldest evidence of the observation of the planet Mercury can be found in Sumerian cuneiform texts dating back to the third millennium BC. The planet is named after the god of the Roman pantheon Mercury, an analogue of the Greek Hermes and the Babylonian Naboo. The ancient Greeks of the time of Hesiod called Mercury. Until the 5th century BC the Greeks believed that Mercury, visible in the evening and morning sky, are two different objects. AT ancient india Mercury was called Buddha and Roginea. In Chinese, Japanese, Vietnamese and Korean Mercury is called the Water Star (in accordance with the ideas of the "Five Elements". In Hebrew, the name of Mercury sounds like "Kokha in Hama" ("Solar Planet").

Natural satellites are relatively small cosmic bodies that revolve around larger "host" planets. In part, a whole science is devoted to them - planetology.

In the 70s, astronomers assumed that Mercury had several celestial bodies, because they caught ultraviolet radiation around. Later it turned out that the light belonged to a distant star.

Modern equipment makes it possible to study the planet closest to the Sun in more detail. Today, all planetary scientists unanimously repeat that it has no satellites.

Moons of the planet Venus

Venus is called similar to the Earth, because they have same formulations. But if we talk about natural space objects, then the planet named after the goddess of love is close to Mercury. These two planets of the solar system are unique in that they are completely alone.

Astrologers believe that Venus could have previously observed such, but to date, not a single one has been found.

How many natural satellites does the earth have?

Our native earth many satellites, but only one natural one, which every person knows from infancy, is the Moon.

The size of the Moon exceeds a quarter of the diameter of the Earth and is 3475 km. It is the only celestial body with such large dimensions relative to the "owner".

Surprisingly, its mass is small at the same time - 7.35 × 10²²² kg, which indicates a low density. Multiple craters on the surface are visible from Earth even without any special devices.

What are the moons of Mars?

Mars is a rather small planet, which is sometimes called red because of its scarlet hue. It is given by iron oxide, which is part of it. Today, Mars boasts two natural celestial objects.

Both moons, Deimos and Phobos, were discovered by Asaph Hall in 1877. They are the smallest and darkest objects in our comic system.

Deimos is translated as the ancient Greek god, sowing panic and horror. Based on observations, it is gradually moving away from Mars. Phobos, named after the god who brings fear and chaos, is the only satellite that is so close to the "owner" (at a distance of 6000 km).

The surfaces of Phobos and Deimos are abundantly covered with craters, dust and various loose rocks.

Moons of Jupiter

To date, the giant Jupiter has 67 satellites - more than any other planet. The largest of them are considered an achievement Galileo Galilei, since they were discovered by him in 1610.

Among the celestial bodies orbiting Jupiter, it is worth noting:

• Adrastea, with a diameter of 250 × 147 × 129 km and a mass of ~3.7 × 1016 kg;
• Metis - dimensions 60 × 40 × 35 km, weight ~ 2 1015 kg;
• Thebe, which has a scale of 116×99×85 and a mass of ~4.4×1017 kg;
• Amalteyu - 250 × 148 × 127 km, 2 1018 kg;
• Io with a weight of 9 1022 kg at 3660×3639×3630 km;
• Ganymede, which, with a mass of 1.5 1023 kg, had a diameter of 5263 km;
• Europe, occupying 3120 km and weighing 5 1022 kg;
• Callisto, with a diameter of 4820 km having a mass of 1 1023 kg.

The first satellites were discovered in 1610, some from the 70s to the 90s, then in 2000, 2002, 2003. The last of them were discovered in 2012.

Saturn and its moons

Found 62 satellites, of which 53 have names. Most of them are composed of ice and rock, with a reflective feature.

The largest space objects of Saturn:

How many moons does Uranus have?

On the this moment Uranus has 27 natural celestial bodies. They are named after characters from famous works written by Alexander Pope and William Shakespeare.

Names and list by quantity with description:

Moons of Neptune

The planet, whose name is consonant with the name of the great god of the seas, was discovered in 1846. She was the first to be found through mathematical calculations, and not through observation. Gradually, new satellites were discovered in her, until 14 were counted.

List

Neptune's moons are named after nymphs and various sea deities from Greek mythology.

The beautiful Nereid was discovered in 1949 by Gerard Kuiper. Proteus is a non-spherical cosmic body and is studied in detail by planetary scientists.

Giant Triton is the iciest object in the solar system with a temperature of -240°C, and also the only satellite that rotates around itself in the opposite direction to the rotation of the "master".

Almost all satellites of Neptune have craters on the surface, volcanoes - both fiery and ice. They spew mixtures of methane, dust, liquid nitrogen and other substances from their depths. Therefore, a person will not be able to be on them without special protection.

What are the "satellites of the planets" and how many of them are there in the solar system?

Satellites are cosmic bodies that are smaller in size than the "host" planets and orbit the latter. The question of the origin of satellites is still open and is one of the key questions in modern planetary science.

To date, 179 natural space objects are known, which are distributed as follows:

• Venus and Mercury - 0;
• Earth - 1;
• Mars - 2;
• Pluto - 5;
• Neptune - 14;
• Uranus - 27;
• Saturn - 63;
• Jupiter - 67.

Technologies are improving every year, finding more celestial bodies. It is possible that new satellites will be discovered soon. We can only wait, constantly checking the news.

The largest satellite in the solar system

The largest moon in our solar system is Ganymede, a moon of the giant Jupiter. Its diameter, according to scientists, is 5263 km. The next largest is Titan with a size of 5150 km - the "moon" of Saturn. Closes the top three Callisto - Ganymede's "neighbor", with whom they share one "owner". Its scale is 4800 km.

Why do planets need satellites?

Planetologists at all times asked themselves the question "Why do we need satellites?" or “What effect do they have on the planets?” Based on observations and calculations, some conclusions can be drawn.

Natural satellites play an important role for the hosts. They create a certain climate on the planet. No less important is the fact that they serve as protection against asteroids, comets, and other dangerous celestial bodies.

Despite such a significant impact, satellites are still not mandatory for the planet. Even without their presence, life can be formed and maintained on it. This conclusion was made by American scientist Jack Lissauer from the NASA Science Space Center.

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

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

In March 2011, several calculated approaches of the probe to Mercury took place, during which the Messenger corrected its orbit and included a fuel saving program. When the maneuvers were completed, the probe was actually an artificial satellite of Mercury, revolving around the planet in an optimal orbit. The messenger from Earth has begun the main part of his mission.

Artificial satellite of Mercury on a space watch

As an artificial satellite of Mercury, the Messenger probe worked until mid-March 2013, flying around the surface at an altitude of about 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 became 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 up of molten metal. There is also a magnetic field, which, however, behaves rather 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 to the collection of scientists was a unique "photo portrait" of the solar system, which was made by the first artificial satellite of Mercury. The photo shows almost all the planets included in solar system except for Uranus and Neptune. Having completed its scientific mission in 2013, the NASA probe has made an invaluable contribution to the development of ideas about space objects closest to the Earth.

The planet's orbit should have been approximately between 5.3 and 7.3 degrees, the longitude of the ascending node was about 183 degrees, the planet's orbital eccentricity was "enormous", and the time it took the planet to cross the sun's disk was 4 hours and 30 minutes. Le Verrier studied these observations and calculated the orbit of the planet: the period of revolution 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 much 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 the Mercury 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 him. Now Wolf's suspicious "sun points" were rekindled in Le Verrier's interest, but it was not until shortly before his death in 1877 that some more detailed "evidence" was published. On April 4, 1875, the 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 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 exciting period after 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 inside the orbit of Mercury: J.C. Watson (Professor of Astronomy at Michigan University) believed he had discovered TWO planets inside the orbit of Mercury! Lewis Swift (who discovered Comet Swift-Tuttle, which returned in 1992) also saw the "star" and determined that it was Vulcan, but it was in a different place than Watson's two "intra-Mercurian" planets. In addition, neither Watson's nor Swift's Volcanoes were consistent with Le Verrier's or Lescarbault's.

After that, no one ever saw Vulcan again, despite the fact that his search was carried out during several total solar eclipses. And in 1916, Albert Einstein published his General Theory Relativity, which explained the deviation in the motion of Mercury without the help of an unknown inner planet. In May 1929, Erwin Freundlich of Potsdam photographed a total solar eclipse in Sumatra and later carefully examined 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 have been found near the Sun.

But what then did these people really see? Lescarbault had no reason to tell fictitious stories, and even Le Verrier believed him. Probably 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 suggested that he saw an intra-Mercurian planet. Swift and Watson could, in brief minutes of observing a complete solar eclipse not correctly identify some stars, believing that they saw Vulcan.

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

Moons of Mercury, 1974

Two days before March 29, 1974, when Mariner 10 reached Mercury, one of the instruments began to register strong ultraviolet radiation that "had no existence there." It disappeared the next day. Three days later it reappeared and its "source" seemed to separate from Mercury. At first, astronomers thought they saw a star. But they saw it in two completely opposite directions, and besides, such hard ultraviolet radiation cannot propagate very far through interstellar space. Therefore, it was assumed that the object should be closer. Does Mercury have a moon?

After a thrilling Friday, when it was calculated that the "object" was moving at 4 km/sec (a speed consistent with being a satellite), JPL management was called. Everyone began to worry about the press conference scheduled for no later than Saturday. Do I need to tell about a suspicious satellite? But the press already knew. Some newspapers - large, more respectable - gave honest information; many others have come up with thrilling stories about Mercury's new moon.

What is a "satellite"? It was moving directly from Mercury and was finally identified as the hot star 31 Crateris (the constellation of the Chalice). Where did the original radiation come from, which was recorded on the way to the planet, remains unknown. Thus ended the story of the moons of Mercury, but at the same time, new chapters in astronomy began: as it turned out, the strong ultraviolet is not completely absorbed by the interstellar medium, as previously thought. The Sails Nebula (Gum Nebula) has been found to be a fairly strong source of extreme ultraviolet with a wavelength of 540 angstroms spanning 140 degrees across the night sky. Astronomers have opened a new window through which the heavens can be observed.

Nate, satellite of Venus, 1672-1892

In 1672, Giovanni Domenico Cassini, one of the most famous astronomers of the time, noted the presence of a small dot near Venus. Maybe Venus has a moon? Cassini decided not to advertise his observations, but 14 years later in 1686 he saw the object again and then entered an entry about it in his diary. He estimated that the diameter of the object is about 1/4 that of Venus and that it shows the same phase as Venus. Later, other well-known astronomers saw this object, such as: James Short in 1740, Andreas Mayer in 1759, Lagrange in 1761 (Lagrange stated that the orbital plane of the satellite is perpendicular to to the ecliptic). In the period of 1761, the object with the sum was seen 18 times by 5 independent observers. Scheuten's observations on June 6, 1761 were particularly interesting: he saw Venus as she crossed the disk of the Sun, accompanied by a small dark dot on one side, which followed Venus across the disk of the Sun. However. Samuel Dunn of Chelsea, England, who also observed Venus crossing the Sun, did not see this extra point. In 1764, two observers saw this satellite 8 times. Other observers also tried to see him, but were unable to find him.

So the astronomical world was divided into two parts: some observers reported that they saw a satellite, while others claimed that they could not find it, despite their best efforts. In 1766, the director of the Vienna Observatory, Father Hell, published a treatise stating 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 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 Venus radii, the period of revolution 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 passage of Venus across the disk of the Sun on June 1, 1777 (Obviously, Lambert made a mistake when 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 the mass of the Earth (this is very badly consistent with a period of 11 days, which is only a little more than 1/3 of the Moon's orbital period.)

In 1768, Christian Horrebow of 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 a satellite have failed. Much later, F.Schorr from Germany attempted to publish the facts about the satellite in a book published in 1875.

In 1884, M. Hozeau, the first director of the Royal Observatory in Brussels, suggested 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 makes a revolution around the Sun in 283 days and finds itself in conjunction with Venus once in 1080 days. Ozo also named her Neith, after the mysterious Egyptian goddess from Sais.

Three years later, in 1887, Ozo revived the "satellite of Venus". The Belgian Academy of Sciences has published a large article where all the observations presented have been examined in detail. Several observations of the satellite turned out to be really stars that were visible in the neighborhood of Venus. Roedkier's observations "were verified" particularly well - they matched the stars of Orion, Taurus, 71 Orions and Gemini! James Short did indeed see a star fainter than magnitude 8. All the observations of Le Verrier and Montaigne could be explained in this way. Orbital calculations of Lambert (Lambert) were refuted. The most recent observations of Horrebow in 1768 were attributed to the star Libra.

After the publication of this article, only one observation report was made - by an observer who had previously tried to detect a satellite of Venus, but could not do it: on August 13, 1892, E.E. Barnard (E.E. Barnard) registered an object of 7 magnitude near Venus. There are no stars in the place that Barnard noted, and "Barnard's eyes lit up with proverbial admiration." We still don't know what he saw. Was it an uncharted asteroid? Or is it short lived new star that no one else has noticed?

The second satellite of the Earth, from 1846 to the present day

In 1846, Frederic Petit, the director of Toulouse, announced that the second satellite of the Earth had been discovered. He was spotted by two observers at Toulouse [Lebon and Dassier] and a third by Lariviere at Artenac in the early evening of March 21, 1846. According to Petya's calculations, his 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 11.4 km! Le Verrier, who was also present at the talk, objected that air resistance had to be taken into account, which no one else had done in those days. 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 motion of a small satellite of the Earth, which is the cause of some (then unexplained) features in the motion of our main moon. Astronomers usually ignore such claims and the idea would have been forgotten if the young French writer, Jules Verne, had not read the summary. In J.Verne's novel "From a Cannon to the Moon", it appears to use a small object approaching close to the capsule to travel through outer space, because of which it flew around the Moon, and did not crash into it: "This," said Barbicane, "is a simple , but a huge meteorite held as a satellite by the Earth's gravity."

"Is that possible?" Michel Ardan exclaimed, "Earth has two satellites?"

“Yes, my friend, it has two satellites, although it is generally 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 detect 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," answered Barbicane, "but if they met him, as we did, 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 they were both approaching, it would have to be retrograde. 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 be in the shadow of the Earth for some more time.

Dr. R.S. Richardson of the Mount Wilson Observatory attempted in 1952 to numerically estimate the eccentricity of the satellite's orbit: the perigee height was 5010 km, and the apogee was 7480 km above the Earth's surface, the eccentricity was 0.1784.

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

In addition to ephemeral satellites, there are two other interesting possibilities. One of them is that the Moon has its own satellite. But, despite intensive searches, nothing was found. time, in a few years or decades). Another suggestion is that there may be Trojan satellites, i.e. additional satellites in the same orbit as the Moon, rotating 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 with a good telescope. He expected to find a sufficiently 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 (Wilkowski) suggested that there may be many tiny bodies too small to be seen separately, but large enough to look like a cloud of dust. In this case, it would be better to observe them without a telescope, i.e. to the naked eye! The use of a telescope will "enlarge them to a state of non-existence". Dr. Kordilevsky agreed to try. It took a dark night clear sky and the moon below the horizon.

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

So the search for a second satellite of the Earth, a century long, apparently came to success, after all 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 counter-radiance.

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, semi-major axis - 14065 km, with perigee and apogee at altitudes of 680 and 14700 km, respectively. Bargby believed they were parts of a large body that collapsed in December 1955. He justified the existence of most of his supposed satellites by the perturbations 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 sometimes may contain a large error, and therefore cannot be used for accurate scientific calculations and analysis. In addition, it can be deduced from Bargby's own observations that although at perigee these satellites should be first magnitude objects and should be clearly visible to the naked eye, no one has ever seen them that way.

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

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

The first person to suggest that Mars had moons was in 1610 Johannes Kepler. In an attempt to solve Galileo's anagram regarding Saturn's rings, Kepler suggested that Galileo discovered the moons of Mars instead.

In 1643, the Capuchin monk Anton Maria Shyrl claimed to have actually seen the moons of Mars. We now know that this was not possible with the telescopes of the time - Shirl probably made a mistake when he saw a star near Mars.

In 1727, Jonathan Swift, in his work Gulliver's Travels, wrote about two small satellites revolving around Mars, known to Laputian 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, close enough to the values ​​predicted by Jonathan Swift 150 years earlier!

14th Satellite of Jupiter , 1975-1980

In 1975, Charles Kowal of the Palomar Observatory (discoverer of Comet 95 P/Chiron) photographed an object, believing it to be a new moon of Jupiter. It was visible several times, but not enough to determine its orbit, and then disappeared. It was mentioned as found in notes to texts until the end of the seventies.

The ninth and tenth moons of Saturn , 1861, 1905-1960, 1966-1980

In April 1861, Hermann Goldschmidt announced the discovery of Saturn's 9th moon, which orbits the planet between Titan and Hyperion. He called this satellite Chiron, also as Pluto's satellite is called today!). However, this discovery was not confirmed - no one has ever seen this satellite again. Later, in 1898, Pickering discovered what is now considered Saturn's 9th moon, Phoebe. For the first time, a satellite of another planet was discovered using photographic observations. Phoebe is also the outermost moon of Saturn.

In 1905, Pickering, however, discovered the tenth moon, which he named Themis. According to Pickering's data, it revolved around Saturn between Titan and Hyperion in a highly inclined orbit: the average distance from Saturn is 1,460,000 km, the orbital period is 20.85 days, the eccentricity is 0.23, the angle of inclination is 39 degrees. Themis was never seen again, but nevertheless, reports of him appeared in almanacs and astronomy books in the 1950s and 1960s again and again.

In 1966, A. Dollfus discovered another new moon of Saturn. Who was named Janus. It revolves around Saturn, only on the outer side 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 seen edge-on. It happened in 1966. Janus is now the tenth moon of Saturn.

In 1980, when the rings of Saturn were seen edge-on again. A flurry of observations has revealed many new moons of Saturn near the rings. Another satellite 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-orbital satellites. That's why the "tenth satellite of Saturn", discovered in 1966, actually turned out to be two different satellites! The Voyager 1 and Voyager 2 spacecraft, which subsequently visited Saturn, confirmed this.

Six Moons of Uranus , 1787

In 1787, William Herschel announced the discovery of six moons of Uranus. Here Herschel made a mistake - only two of these six satellites actually existed: Titania and Oberon - the largest and outermost. The remaining four were the only ones that happened to be nearby (... I think I've heard this story somewhere before... :-)

Planet X , 1841-1992

In 1841, John Couch Adams began to investigate the reasons for the rather large deviation in the motion of Uranus from the calculated one. In 1845, Urban Le Verrier began research in the same area. Adams presented two different solutions to this problem, suggesting that gravitational interaction with an unknown planet could be the cause of the deflection. Adams tried to present his solution at the Greenwich Observatory, but because he was young and unknown, he was not taken seriously. Urban Le Verrier presented his solution in 1846, but France did not have the necessary equipment to detect this planet. Then Le Verrier turned to the Berlin Observatory, in which Galle (Galle) and his assistant D "Arrest (d" Arrest) on the evening of September 23, 1846 found Neptune. Today, both Adams and Le Verrier share the laurels of predicting the existence and position of Neptune.

(Inspired by this success, Le Verrier took on the problem of Mercury's orbital deviation and proposed the existence of the intra-Mercurian planet Vulcan, which, as it turned out, did 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 satellite Triton was discovered, with which it proved easy to measure the mass of Neptune with great accuracy. It turned out to be 2% more than expected from calculations of its interaction with Uranus. It looked as if the deviations in the motion of Uranus were actually caused by two planets, especially considering that the actual orbit of Neptune differed markedly 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 checked the reference stars that Ferguson used. Hind was unable to find one of Ferguson's reference stars. Maury of the Naval Observatory also failed to find this star. For several years, it was believed that this was the observation of another planet, but in 1879 another explanation was proposed: Ferguson made a mistake when recording his observations - when this mistake was corrected, another star fit well as the "lost reference star".

The first serious attempt to find trans-Neptunian planets was made by David Todd in 1877. He used " graphic method and, in spite of ill-defined deviations in the motion of Uranus, determined the elements for the trans-Neptunian planets: mean distance 52 AU, period 375 years, magnitude weaker than 13. Their longitude for the period 1877-84 was given as 170 degrees with an error of 10 degrees, the orbital inclination 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 aphelia of periodic comets tend to cluster around the orbit of the major planets. Jupiter largest number such comets, Saturn, Uranus and Neptune also have some 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 an 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 (Forbes) published a memoir concerning the aphelion of comets and their relationship with planetary orbits. By the beginning of 1900, 5 aphelion comets 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 a distance of 41.25 AU. with a period of 272 years, "Trans-Ocean" at 56 a.u. 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 from Munster (Germany), suggested in 1902 a planet the size of Uranus at 50 AU. and with a period of 360 years, which he called "Hades" (Hades). Grigull based his work mainly on the orbits of comets whose aphelions lay beyond the orbit of Neptune. There they could experience the gravitational influence of the body, which caused a noticeable deviation in the motion of Uranus. In 1921, Grigull revised the value of the orbital period of Hades, as the value of 310-330 years was more suitable to explain the observed deviations.

In 1900, Hans-Emil Lau from 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 magnitudes around 10-11 magnitudes. The longitude of these hypothetical planets for 1900 should have been 274 and 343 degrees, but with a very large error for common planets (up to 180 degrees).

In 1901, Gabriel Dallet concluded that there was 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 at the epoch of 1900. In the same year, Theodor Grigull deduced the longitude of the trans-Neptunian planet, which differed by less than 6 degrees from the value for the planet Dalle, and later the difference decreased to 2.5 degrees. This planet was supposed to be at a distance of 50.6 a.u.

In 1904, Thomas Jefferson proposed the existence of three trans-Neptunian planets with semi-axes 42.25, 56 and 72 AU. The most inner planet had a period of 272.2 years and a longitude of 200 degrees in 1904. Russian general Alexander Garnovsky suggested four hypothetical planets, but failed 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 "Search for 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 got different results.

Pickering used graphical analysis and believed that "Planet O" is at a distance of 51.9 a.u. with a period of 373.5 years, twice the mass of the Earth and a magnitude of 11.5-14 magnitudes. Pickering, over the next 24 years, proposed eight other trans-Neptunian planets. Pickering's results were the reason for Galiot's correction of 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 orbital elements for the O and P planets determined bodies quite 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 suggested that planet Q had a mass of 20,000 Earth masses, making it 63 times as massive as Jupiter, or about 1/6 the mass of the Sun, closer to the minimum mass star than to the planet. Also 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 mass of the planet at 20 Earth masses and the brightness at about 11 magnitudes. In 1931, after the discovery of Pluto, he changed the parameters of the orbit 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 suggested planet S in 1928, and estimated its orbital elements in 1931: the distance from the Sun is 48.3 AU. (which is close to Lowell's Planet X value of 47.5 AU), period 336 years, mass 5 Earth masses, magnitude 15 m . In 1929, Pickering proposed the planet U, at 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. Pickering's last proposed planet was Planet T, which he predicted in 1931: semiaxis 32.8 AU, period 188 years.

Elements of the orbit of planet O in different years:

Year Mean Period Mass Sound-magn. Node Tilt Longitude distance (years) (Earth masses) 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 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 came 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: at epoch 1850-01-01, the mean longitude was 11.67 degrees, the perigee longitude was 186 , eccentricity 0.228, average distance 47.5 AU from the Sun, ascending node longitude 110.99 degrees, orbital inclination 7.30 degrees, planet mass 1/21000 of the Sun's mass. Lowell and other astronomers searched in vain for Planet X in 1913-1915. In 1915, Lowell published his theoretical results on Planet X. Ironically, in the same 1915, two fuzzy images of Pluto were recorded at the Lowell Observatory, although they could not be recognized as images of the planet until its "official" discovery in 1930 year. Lowell's failure to find Planet X was his biggest 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 1,000 image plates he obtained during his second search attempt, 515 asteroids, 700 different stars, and 2 images of Pluto were later found!

The 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. Tombo began his work in April 1929. On January 23 and 29 of this year, Tombo photographed several photographic plates on which he found Pluto on February 18 while exploring them. By that time, Tombo had already examined hundreds of pairs of such plates with millions of stars. The search for Planet X has come to an end.

By the end? The new planet, later named Pluto, turned out to be disappointingly small, with a mass probably one Earth mass, and perhaps only 1/10 of the Earth's mass or even less (in 1979, when Pluto's satellite Charon was discovered, it turned out that the mass of the Pluto-Charon pair is about 1/400 of the mass of the Earth!). Planet X must, if, of course, it is she who is causing the disturbances in the orbit of Uranus, be much larger than this! Tombo 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 magnitudes. Tombo examined about 90 million images of almost 30 million stars in more than 30,000 square degrees of the celestial sphere. He discovered one new globular cluster, 5 new open star clusters, one supercluster of 1800 galaxies and several small clusters of galaxies, one new comet, about 775 new asteroids -- but none more. new planet except for Pluto. Tombo concluded that there were no unknown planets brighter than 16.5 magnitude - only planets in almost polar orbits or located close to the south celestial pole could not fall into the field of his research and not be discovered. He hoped to find a Neptune-sized planet at seven times the distance of Pluto, or a Pluto-sized planet at 60 AU.

Giving Pluto its name constitutes 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 have suggested naming her 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 parameters of the orbit calculated for Pluto gave an eccentricity of 0.909, and a period of 3000 years! This casts some doubt as to whether this was the same planet we know today or not. However, a few 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 (mean distance) 43.0 55.1 39.5 e (eccentricity) 0.202 0.31 0.248 i (tilt) 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. Jan 1991 2129 Sept. 1989 u (annual motion) 1.2411 0.880 1.451 P (period, years) 282 409.1 248 T (date of passage of perig.) 1991.2 2129.1 1989.8 E (longitude 1930.0) 102.7 102.6 108.5 m (mass, Earth=2.0 M 06) 6.06 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 absolutely unsuitable for having a tangible 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 was actually a happy accident, or rather the result of an elaborate search by Clyde Tombaugh.

Mass of Pluto:

Crommelin 1930: 0.11 Earth masses 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 from Ottawa (Canada) - it was 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 facility" 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 on theoretical grounds (Lowell himself had already predicted a second trans-Neptunian planet at about 75 AU). In 1946, Francis M.E. Sevin proposed the existence of a trans-Plutonic planet at a distance of 78 AU. He made this conclusion based on a strange empirical method in which he divided the planets and the asteroid Hidalgo into two groups of inner and outer bodies:

Group I: Mercury Venus Earth Mars Asteroids Jupiter Group II: ? Pluto Neptune Uranus Saturn Hidalgo Then he added the logarithms of the periods of each pair of planets, getting an approximately constant sum of about 7.34. Assuming that the pair from Mercury and trans-Pluto would give the same amount, he got a period of about 677 years for Transpluto. Sevin later calculated the complete set of elements of the Transpluto orbit: 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 from eight periodic comets to predict a trans-Plutonic planet at 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 brightness is about 11 magnitude. In 1957, Kitzinger revised this problem and obtained new orbital elements: distance 75.1 AU, period 650 years, inclination 40 degrees, magnitude about 10. After an unsuccessful photographic search, 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 angle of inclination 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 found.

Halley's Comet has also been used as a detection "probe" for trans-Plutonic planets. In 1942, R.S. Richardson discovered that an Earth-sized planet at a distance of 36.2 AU from the Sun or 1 AU from the aphelion of Halley's comet, should delay the passage of its perihelion, which was in good agreement with observations. Planet at 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 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 on its 1456 perihelion passage. This giant trans-Plutonic planet was also searched for but not found.

Tom van Flandern explored 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. The orbit of Uranus coincided with observations during one revolution, but not on the previous revolution. In 1976, Tom van Flandern became convinced that it was caused by the tenth planet. After the discovery of Charon in 1978, which showed that the mass of Pluto was actually much less than expected, van Flandern convinced his colleague at USNO Robert S. Harrington (Robert S. Harrington) that the tenth planet exists. They began to cooperate in the study of the satellite system of Neptune. Soon their views diverged. Van Flandern believed that the tenth planet was formed beyond the orbit of Neptune, while Harrington believed that it was the orbits of Uranus and Neptune. Van Flandern believed that more data was needed, such as the corrected mass of Neptune obtained from Voyager 2. Harrington, on the other hand, began the search for the planet with inhuman zeal - starting in 1979, he still did not find any planet until 1987. Van Flandern and Harrington suggested that the tenth planet could be near aphelion in a highly elliptical orbit. If the planet is dark, it may not be brighter than 16-17 magnitude, (this assumption was put forward by van Flandern).

In 1987, Whitmire and Matese predicted a tenth planet at a distance of 80 AU. with a period of 700 years and an orbital inclination 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 suggested by Whitemire and Mates (see below).

In 1987, JPL's John Anderson tested the motions of the Pioneer 10 and Pioneer 11 spacecraft to see if their motions were deflected by gravitational forces from unknown bodies. Nothing was found - from this Anderson concluded that the tenth planet most likely exists! JPL excluded observations of Uranus before 1910 from their calculation of ephemeris, 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 Earth masses, the orbital period is about 700-1000 years, and the orbit has a strong inclination. Its influence on the inner planets will not be discovered again until at least 2600. Anderson hoped that the Voyagers would help determine the position of this planet.

Conley Powell of JPL also analyzed planetary motion. He also found that the observations of Uranus matched the 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 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 that of Pluto! Accordingly, the new Powellian planet should be in the constellation Leo and have a brightness of about 12 magnitudes. However, Powell himself thinks that these data are too early for the search for the planet and need further verification.

Even if trans-Plutonic planets are never found, the outer solar system will still be the focus of researchers' attention. 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 program to search 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 of 6.923 degrees, and a diameter of about 50 km. During this search, Koval 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 look very much like a comet, and later it even acquired a short cometary tail! In 1995, Chiron was also classified as a comet - certainly the largest comet we know of.

In 1992, another distant asteroid was discovered: Pholus. Later, in 1992, an asteroid beyond Pluto was discovered, followed by five more trans-Plutonic asteroids discovered in 1993, and finally more than ten more in 1994!

However, the spacecraft Pioneer 10 and 11, Voyager 1 and 2, crossed the outer solar system, and could also be used as "probes" to detect unknown gravitational influences, possibly caused by unknown planets - but nothing was found. The Voyagers also established more accurate masses for the outer planets -- when these updated data were used to numerically integrate motions in the solar system, all the controversy surrounding the positions of the outer planets finally disappeared. It seems that the search for "Planet X" has finally come to an end. "Planet X" didn't exist (Pluto doesn't really count), but instead an asteroid belt was discovered beyond the orbits of Neptune and Pluto! Asteroids beyond the orbit of Jupiter, which were discovered in August 1993, are presented below:

Asteroid a e Sun. Arg perig. Avg. Period Name a.u. deg. deg. deg. deg. year. 944 5.79853 .658236 42.5914 21.6567 56.8478 60.1911 14.0 Идальго 2060 13.74883 .384822 6.9275 209.3969 339.2884 342.1686 51.0 Хирон 5145 20.44311 .575008 24.6871 119.3877 354.9451 7.1792 92.4 Фолус 5335 11.89073 .866990 61.8583 314.1316 191.3015 23.3556 41.0 Дамокл 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 The following trans-Neptunian asteroids were discovered in November 1994:
Object a e incl. R Sv. Diam. The Discoverer a.u. was discovered. deg. 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 1993 Sep 1993 RP 39.3 0.114 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.14 2.1AL 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 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 May 1994 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 1994 Jewitt & Chen 1994 TG 42.3 0 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 the 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, a companion star of the Sun, from 1983 to the present

Suppose that our Sun is not a single star, but has a companion. Suppose this companion star moves in an elliptical orbit, its distance from the Sun varies between 90,000 AU. (1.4 light years) and 20,000 AU, with a period of 30 million years. Also suppose that this star is dark, or at least very faint, and therefore we did not notice it before.

This should mean that once every 30 million years, this hypothetical companion star of the Sun must pass through the Oort cloud (a hypothetical cloud of proto-comets that is at a very large distance from the Sun). During this passage, proto-comets in the Oort cloud around this star will "churn". And in a few tens of thousands of years, here on Earth, we might notice a catastrophic increase in the number of comets traversing the inner parts of the solar system. If the number of comets increases very much, then the Earth runs the risk of colliding with the nucleus of one of them.

In the study of the geological history of the Earth, it was found that about once every 30 million years on Earth there was a mass extinction of living beings. The most famous of these is, of course, the extinction of the dinosaurs about 65 million years ago. According to this hypothesis, in about 15 million years from today, the time will come for another mass extinction of life.

The "deadly companion" hypothesis of the Sun was proposed in 1985 by Daniel. Whitemeier (Daniel P. Whitmire) and John D. Mates (John J. Matese) from the University of South Louisiana (USA). This star even got a name: Nemesis (Nemesis). The only unpleasant moment in this hypothesis is that there are no indications at all of the existence of a companion star near the Sun. She needs to be very bright or massive, even a star much smaller and dimmer than the Sun and she would be noticed, even a brown or black dwarf (a planet-like body is not massive enough to start the process of "burning hydrogen" 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 found for it (namely, a 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, then few would doubt that this is the primary cause of the periodic extinction of species on Earth.

But this hypothesis has all the premises of a myth. If an anthropologist of a previous generation had heard such a story from his informers, he would no doubt have used words such as "primitive" or "pre-scientific" when he finished writing it in his next volume of academic writings. Listen, for example, to the following story: There is another Sun in the sky, the Demon Sun, which we cannot 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 Demon Sun had attacked many times before. And 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 skeptically joked: we are always in danger of deceiving ourselves. But even if this theory has no solid foundation, it is still serious and quite valid, because its main idea can be tested: you find a star and test its properties.

However, since the IRAS satellite surveyed the entire sky in the infrared range and found no radiation from the Nemesis in it, its existence has become very unlikely.

Links

(Sorry, but all links given by the author are given to English-language sources. Note Ed.)

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 page 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