The Messenger interplanetary probe 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, remote from Earth, and collect data of interest to scientists. The unique flight of the spacecraft attracted the attention of many researchers, eagerly 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, since 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 calculated rendezvous of the probe with Mercury took place, during which Messenger corrected 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, revolving around the planet in an optimal orbit. The messenger from Earth began the main part of his mission.
Artificial satellite of Mercury on the space watch
As an artificial satellite of Mercury, the Messenger probe worked until mid-March 2013, circling the surface at an altitude of about 200 km. During its stay near the planet, the probe collected and transmitted a lot of useful information to the Earth. Much of the data was so unusual that it 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. The core of Mercury is made 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 for the scientists was a unique "photo portrait" of the solar system, which was made by the first artificial satellite of Mercury. The photo captures 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 the space objects closest to Earth.
Flashing before us mainly on the pages of atlases, monitors and TV screens, arouse keen interest. A lot of data has been collected about our solar system over the past century, when the development of space technologies made a leap forward. However, people who are far from astronautics and astronomy do not have such wide knowledge about the planets that are neighbors to the Sun.
We are going to talk about one of the small planets of the solar system in this article. It is the closest to the Sun, one of the smallest. What secret do you think this is heavenly body? To solve it, you must first remember whether there are satellites of Mercury. Difficult, isn't it? And now we go on a journey into entertaining astronomical facts.
What do we already know about Mercury?
In the school curriculum, not too extensive knowledge about the planets of the solar system is given, but sufficient for the general knowledge sector.
Mercury is one of the solar system (after the expulsion of Pluto outside the planetary system, it is the smallest). It is also closest to the Sun.
The planet has a small mass relative to our Earth (only 1/20). Wherein most The object's body is made up of a liquid core, which some researchers believe contains high levels of iron.
In addition, we also know how many satellites Mercury has: it does not have them. However, not everything turned out to be so unambiguous in the world of astronomers.
Mysterious celestial body: the history of the hypothesis
As we have said, the existence of a natural satellite was not a long-term scientific hypothesis. It is interesting on the basis of what conclusions it was put forward at one time.
So it happened in 1974, March 27th. At this time, the Mariner-10 interplanetary station was approaching Mercury. Devices on board the station recorded ultraviolet radiation, which a priori should not have been on this section of the path. At least the astronauts thought so.
The next day there was no radiation. Two days later, on March 29, the station again flew near Mercury and again recorded ultraviolet radiation. According to its characteristics, it could come from the one that separated from the planet.
Scientists' versions of objects near Mercury
Under these conditions, the research team has new data for versions of whether Mercury has satellites. Scientists have several versions about this alleged object. Some were convinced that it was a star, others that it was a satellite. The latter version was supported by some data related to the then topical assumptions about the existence of an interstellar medium.
For a long time, studies of the outer space of Mercury were conducted in order to find the source of ultraviolet radiation. However, neither then, nor now there is no data about that object.
How many satellites does Mercury have?
Thus, we can repeat the hypothesis of scientists and take into account the historical existence of a certain satellite of Mercury. IN this moment there is an unequivocal answer to the question of how many satellites Mercury has - not a single natural one.
About quantity space objects orbiting this planet, there are no data. Only artificial space bodies launched by a man now fit the definition of a satellite of a given celestial body.
So, the satellite of Mercury is a hypothetical space object orbiting the planet, it was considered to be of natural origin. That is, its presence (at least hypothetical) would be the answer to the question of whether there are natural satellites of Mercury. This hypothesis existed for a short time, its adherents became less and less. Subsequently, the first artificial satellite of Mercury was launched. This happened in March 2011. The existence of natural satellites has not been confirmed.
Conclusion
This article touches on an interesting aspect of astronomy that you most likely did not learn about in school. When describing the planets of the solar system, much attention is paid to natural and artificial satellites.
At the current stage of the development of astronomical science, there is no doubt that there are no natural satellites of Mercury. However, there was another period in science when, after capturing ultraviolet radiation in an unusual area of outer space, scientists came up with various hypotheses. Among them were suggestions that natural satellites of Mercury exist.
What other mysteries will space present in such a space as ours? solar system, we can only guess and rely on science fiction writers. Perhaps the satellites of Mercury and other cosmic bodies, which planetary science does not suspect now, will still be discovered.
Flashing before us mainly on the pages of atlases, monitors and TV screens, arouse keen interest. A lot of data has been collected about our solar system over the past century, when the development of space technologies made a leap forward. However, people who are far from astronautics and astronomy do not have such wide knowledge about the planets that are neighbors to the Sun.
We are going to talk about one of the small planets of the solar system in this article. This is the planet Mercury, closest to the Sun, one of the smallest. What secret do you think this heavenly body conceals in itself? To solve it, you must first remember whether there are satellites of Mercury. Difficult, right? And now we go on a journey into entertaining astronomical facts.
What do we already know about Mercury?
In the school curriculum, not too extensive knowledge about the planets of the solar system is given, but sufficient for the general knowledge sector.
Mercury is one of the smallest planets in the solar system (after Pluto was expelled outside the planetary system, it is the smallest). It is also closest to the Sun.
The planet has a small mass relative to our Earth (only 1/20). At the same time, most of the object's body is a liquid core, which, according to some researchers, contains a high level of iron.
In addition, we also know how many satellites Mercury has: it does not have them. However, not everything turned out to be so unambiguous in the world of astronomers.
Mysterious celestial body: the history of the hypothesis
As we have said, the existence of a natural satellite was not a long-term scientific hypothesis. It is interesting on the basis of what conclusions it was put forward at one time.
So it happened in 1974, March 27th. At this time, the Mariner-10 interplanetary station was approaching Mercury. Devices on board the station recorded ultraviolet radiation, which a priori should not have been on this section of the route. At least the astronauts thought so.
The next day there was no radiation. Two days later, on March 29, the station again flew near Mercury and again recorded ultraviolet radiation. According to its characteristics, it could come from a space object that separated from the planet.
Scientists' versions of objects near Mercury
Under these conditions, the research team has new data for versions of whether Mercury has satellites. Scientists have several versions about this alleged object. Some were convinced that it was a star, others that it was a satellite. The latter version was supported by some data related to the then topical assumptions about the existence of an interstellar medium.
For a long time, studies of the outer space of Mercury were conducted in order to find the source of ultraviolet radiation. However, neither then, nor now there is no data about that object.
How many satellites does Mercury have?
Thus, we can repeat the hypothesis of scientists and take into account the historical existence of a certain satellite of Mercury. At the moment, there is an unambiguous answer to the question of how many satellites Mercury has - not a single natural one.
There is no data on the number of space objects orbiting this planet. Only artificial cosmic bodies launched by man now fit the definition of a satellite of a given celestial body.
So, the satellite of Mercury is a hypothetical space object orbiting the planet, it was considered to be of natural origin. That is, its presence (at least hypothetical) would be the answer to the question of whether there are natural satellites of Mercury. This hypothesis existed for a short time, its adherents became less and less. Subsequently, the first artificial satellite of Mercury was launched. This happened in March 2011. The existence of natural satellites has not been confirmed.
Conclusion
This article touches on an interesting aspect of astronomy that you most likely did not learn about in school. When describing the planets of the solar system, much attention is paid to natural and artificial satellites.
At the current stage of the development of astronomical science, there is no doubt that there are no natural satellites of Mercury. However, there was another period in science when, after capturing ultraviolet radiation in an unusual area of outer space, scientists came up with various hypotheses. Among them were suggestions that natural satellites of Mercury exist.
What other mysteries will present space in such a space as our solar system, we can only guess and rely on science fiction writers. Perhaps the satellites of Mercury and other cosmic bodies, which planetary science does not suspect now, will still be discovered.
The planet's orbit should be approximately between 5.3 and 7.3 degrees, the longitude of the ascending node was about 183 degrees, the eccentricity of the planet's orbit was "huge", and the time it took 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 account for the deviation of the Mercury orbit, but perhaps the largest of the asteroids in the intra-Mercury 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 Le Verrier's interest was revived by Wolf's suspicious "sunspots", but it was not long 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. In the orbit calculated by Le Verrier, the planet was supposed to cross the Sun on April 3 of this year, and Wolff 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 on 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: JC Watson (Michigan Professor of Astronomy University) believed that he had discovered TWO planets inside the orbit of Mercury! Lewis Swift (who discovered the Swift-Tuttle comet that returned in 1992) also saw the "star" and determined it to be Vulcan, but it was in a different location from the two Watsonian "intra-Mercurian" planets. In addition, neither the Watsonian nor the Swift Volcanoes were consistent with the Le Verrier or Lescarbot Volcanoes.
After that, no one ever saw Vulcan again, despite the fact that his searches were carried out during several total solar eclipses. And in 1916, Albert Einstein published his General Theory of 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 studied the images, which turned out to be 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 found near the Sun.
But what then did these people really see? Lescarbaud had no reason to tell fictional stories, and even Le Verrier believed him. Lescarbo probably saw a small asteroid passing very close to Earth, just inside the Earth's orbit. At that time, such asteroids were not yet known, so Lescarbo assumed that he saw an intra-Mercurian planet. Swift and Watson could not correctly identify some of the stars in the brief minutes of observing a total solar eclipse, believing that they saw Vulcan.
The "volcano" came to life briefly in 1970-1971, when some researchers thought that during a total solar eclipse they found several obscure objects close to the Sun. These objects could be 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 detecting strong ultraviolet radiation that "did not exist there." It disappeared the next day. Three days later, it appeared again and its "source" seemed to be separated 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 travel very far through interstellar space. Therefore, it was assumed that the object should be closer. Does Mercury have a satellite?After an exciting Friday, when the "object" was calculated to be moving at 4 km / sec (a speed consistent with being a satellite), the JPL leadership was called out. Everyone began to worry about a press conference scheduled no later than Saturday. Do I need to tell you about a suspicious satellite? But the press already knew. Some newspapers — the larger, more respectable — gave honest information; many others have come up with exciting stories about the new moon of Mercury.
And what about the "satellite"? It moved directly from Mercury and was definitively identified as the hot star 31 Crateris (the constellation of the Chalice). Where did the initial radiation come from, which was recorded on the approach to the planet, remains unknown. This is how the story of the satellites of Mercury ended, but at the same time new chapters in astronomy began: as it turned out, strong ultraviolet light is not completely absorbed by the interstellar medium, as was previously assumed. It was discovered that the Gum Nebula is a fairly strong source of extreme ultraviolet radiation with a wavelength of 540 angstroms spreading 140 degrees across the night sky. Astronomers have opened a new window through which the heavens can be viewed.
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 satellite? Cassini decided not to advertise his observations, but 14 years later in 1686, he saw the object again and then wrote about it in his diary. He estimated that the object's diameter is about 1/4 that of Venus and that it shows the same phase as Venus. Later, this object was seen by other well-known astronomers, such as: James Short in 1740, Andreas Mayer in 1759, Lagrange (JLLagrange) in 1761 (Lagrange stated that the orbital plane of the satellite is perpendicular to to the ecliptic). During 1761, the object was seen 18 times by 5 independent observers. Scheuten's observations on June 6, 1761 were particularly interesting: he saw Venus as it crossed the solar disk, accompanied by a small dark dot on one side that followed Venus crossing the solar disk. But. Samuel Dunn of Chelsea, England, who also observed Venus crossing the Sun, did not see this additional 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 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 where 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 it 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 times the radius of Venus, the orbital period is 11 days 3 hours, the orbital inclination 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 in calculating the orbital elements: the 66.5 radius of Venus is almost the same as from our Moon to the Earth, the mass of Venus is slightly less than the mass of the Earth. This is very poorly consistent with the period of 11 days, which is only slightly more than 1/3 of the orbital period of the Moon.)
In 1768, Christian Horrebow of Copenhagen once again observed the satellite. Three more attempts were made to find him, 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 tried 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, 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 orbits 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 revived the "moon of Venus". The Belgian Academy of Sciences published a long article where all the observations presented were investigated in detail. Several observations of the satellite turned out to be indeed stars that were visible in the vicinity of Venus. Roedkier's observations were "tested" especially well - they matched the stars of Orion, Taurus, 71 Orion and Gemini! James Short actually saw a star fainter than magnitude 8. All observations by Le Verrier and Montaigne could be explained in a similar way. Lambert's orbital calculations were disproved. The most recent sightings 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 find a satellite of Venus, but could not do this: on August 13, 1892, E.E. Barnard registered a 7th magnitude object near Venus. There are no stars in the place that Barnard noted and "Barnard's eyes lit up with notorious admiration." We still don't know what he saw. Was it an uncharted asteroid? Or is it a short-lived new star that no one else has seen?
Second Earth Satellite, from 1846 to the present day
In 1846, Frederic Petit, director of Toulouse, announced that a second Earth satellite 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 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 only 11.4 km perigee! Le Verrier, who was also present at the lecture, argued that it was necessary to take air resistance into account, which no one 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 movement 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 resume. In J. Verne's novel "From a Cannon to the Moon", he uses a small object approaching close to the capsule to travel through outer space, which is why it flew around the moon, and did not crash into it: "This," said Barbicane, "is simple but a huge meteorite held as 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 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," replied Barbicane, "but if they, like us, met him, they would no longer hesitate.... But this gives us the opportunity to determine our position in space... The distance to him is known and we were, hence, 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:
- A satellite at 7480 km above the Earth's surface should have an orbital period of 4 hours 48 minutes, not 3 hours 20 minutes
- Since he was visible through a window through which the Moon was also visible, and since they were both approaching, he would have to have retrograde motion. This is an important point that Jules Verne does not mention.
- In any case, the satellite must be in an eclipse (by the Earth) and therefore not visible. The metal projectile was supposed to be in the shadow of the Earth for some time.
Nevertheless, Jules Vernovsky is Petit's second companion (Petit in French - small) is known all over the world. Amateur astronomers concluded that this was a good opportunity to achieve fame - someone who discovered this second satellite could write his name in the scientific chronicles. None of the large observatories 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") - of course they never found Kleinchen.
In addition to the ephemeral satellites, there are two other interesting possibilities. One is that the moon has its own satellite. But, despite the intensified searches, nothing was found (We add that, as we now know, the gravitational field of the Moon is very "uneven" or inhomogeneous. This is enough for the rotation of the lunar satellites to be unstable - therefore the lunar satellites fall on the Moon after a very short interval time, after a few years or decades). Another assumption is that there may be Trojan satellites, i.e. additional satellites in the same orbit as the Moon, orbiting 60 degrees in front of 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 hoped to find a large enough body in lunar orbit at a distance of 60 degrees from the Moon. Searches 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 look like 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 to a state of non-existence." Dr. Kordilevsky agreed to try. It required a dark night with a clear sky and the moon below the horizon.
In October 1956, Kordilevsky saw for the first time a distinctly luminous object in one of two expected positions. It was not small, extending about 2 degrees (that is, almost 4 times as large as the Moon itself), and was very dim, half the brightness of the notorious difficulty of observing counterglow (Gegenschein; counterglow 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 the expected positions. They seemed to change in size, but it could have been a change in lighting. J. Roach discovered these satellite clouds in 1975 using the OSO (Orbiting Solar Observatory). In 1990, they were photographed again, this time by the Polish astronomer Winiarski, who discovered that they constituted an object several degrees in diameter, "deviated" 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, apparently, came to success, after all the efforts. Even though this "second satellite" turned out to be completely unlike anything anyone ever imagined. They are very difficult to detect and differ from the zodiacal light, in particular from the anti-radiance.
But people still assume the existence of an additional natural satellite of the Earth. Between 1966 and 1969, John Bargby, an American scientist, stated that he observed at least 10 small natural satellites of the Earth, visible only through a telescope. Bargby found elliptical orbits for all these objects: an eccentricity of 0.498, a semi-major axis of 14065 km, with a perigee and apogee at altitudes of 680 and 14700 km, respectively. Bargby considered them to be parts of a large body that collapsed in December 1955. He justified the existence of most of his supposed satellites by the perturbations that they cause in the movements of artificial satellites. Bargby used data on artificial satellites from the Goddard Satellite Situation Report, not suspecting that the values in these publications are approximate, and sometimes they can contain large errors and therefore cannot be used for accurate scientific calculations and analysis. In addition, as follows from Bargby's own observations, it can be concluded that although at perigee these satellites should be objects of the first magnitude and should be clearly visible to the naked eye, no one saw them like that.
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 orbit directly around the Earth.
Satellites of Mars, 1610, 1643, 1727, 1747, 1750 and from 1877 to the present
The first to suggest that Mars has satellites was Johannes Kepler in 1610. While trying to solve Galileo's anagram concerning the rings of Saturn, Kepler suggested that Galileo had discovered the moons of Mars instead.In 1643, the Capuchin monk Anton Maria Shyrl claimed to have actually seen the satellites of Mars. We now know that this was not possible with the telescopes of that time - probably Shirl was mistaken when he saw a star next to Mars.
In 1727, Jonathan Swift, in his work "Gulliver's Voyage", wrote about two small satellites orbiting Mars, known to the Laputian astronomers. Their circulation periods were 10 and 21.5 hours. These "satellites" were borrowed in 1750 by Voltaire in his novel "Micromegas", which tells about a giant from Sirius who visited our solar system.
In 1747, the German captain Kindermann declared that he saw 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 7 hours 39 minutes and 30 hours 18 minutes, respectively, close enough to the values predicted by Jonathan Swift 150 years earlier!
14th Moon of Jupiter , 1975-1980
In 1975, Charles Kowal of the Palomar Observatory (who discovered Comet 95 P / Chiron) photographed an object as Jupiter's new moon. It was visible several times, but not enough to determine its orbit, and then disappeared. He was referred to as being discovered in the text notes until the late 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 revolves around the planet between Titan and Hyperion. He named this satellite Chiron, also as Pluto's moon is called today!). However, this discovery was not confirmed - no one ever saw this satellite again. Later, in 1898, Pickering discovered what is now Saturn's 9th moon, Phoebe. For the first time, a satellite of another planet was discovered using photographic observations. Phoebe is also Saturn's outermost moon.In 1905, Pickering, however, discovered a tenth satellite, 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, an orbital period of 20.85 days, an eccentricity of 0.23, an inclination angle of 39 degrees. Themis was never seen again, but reports of him appeared in almanacs and astronomy books over and over again in the 1950s and 1960s.
In 1966, A.Dollfus discovered another new moon of Saturn. Which was named Janus. It revolves around Saturn, only on the outside of its rings. It was so weak and close to the rings that the only chance to see it was when Saturn's rings were edge-on. It happened in 1966. Now Janus is the tenth moon of Saturn.
In 1980, when the rings of Saturn were visible from the edge again. A flurry of observations has discovered many new moons of Saturn near the 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 "swap" orbits! It turned out that the Janus, discovered in 1966, was in fact an observable object consisting of both of these co-orbital satellites. This is why the "tenth moon of Saturn" discovered in 1966 actually turned out to be two different satellites! The spacecraft Voyager 1 and Voyager 2, which subsequently visited Saturn, have 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 most external. The remaining four were only those that were nearby (... I think I have already heard this story somewhere before ... :-)Planet X , 1841-1992
In 1841, John Couch Adams began to investigate the reasons for the large deviation of the motion of Uranus from the calculated one. In 1845, Urbain 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 since 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 locate this planet. Then Le Verrier turned to the Berlin Observatory, where Galle and his assistant D "Arrest (d" Arrest) found Neptune on the evening of September 23, 1846. Today, both Adams and Le Verrier share the laurels of predicting the existence and position of Neptune.(Inspired by this success, Le Verrier tackled the problem of the deviation of the orbit of Mercury and suggested the existence of the intra-Mercury planet Vulcan, which, as it turned out, does not exist.)
On September 30, 1846, a week after the discovery of Neptune, Le Verrier announced that there might be another unknown planet there. On October 10, the large satellite of Neptune, Triton, was discovered, with the help of which it turned out to be 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 the two planets, especially when you consider that the actual orbit of Neptune 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 checked the reference stars that Ferguson used. Hind was unable to find one of Ferguson's reference stars. Maury of the Naval Observatory also couldn't find this star. For several years, it was believed that this was an observation of another planet, but in 1879 another explanation was proposed: Ferguson made a mistake in recording his observations - when this error was corrected, another star was well suited for the role of "lost reference star".
The first serious attempt to find trans-Neptunian planets was made by David Todd in 1877. He used the "graphical method" and, despite poorly defined deviations in the motion of Uranus, determined the elements for the trans-Neptune planets: an average distance of 52 AU, a period of 375 years, a magnitude less than 13. Their longitude for the period 1877-84 years 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 aphelions of periodic comets tend to cluster around the orbits of major planets. Jupiter has the largest number of 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 is probably moving at a distance of 45 AU.
A year later, in 1880, Professor Forbes published a memoir concerning the aphelion of comets and their connection with planetary orbits. By the beginning of 1900, 5 comets were known with aphelion on the other side of Neptune's orbit, and then Forbes assumed one trans-Neptune 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 could be found in the outer solar system. Gaillot of the Paris Observatory suggested the existence of two trans-Neptune 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 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, suggested in 1902 a planet the size of Uranus at 50 AU. and with a period of 360 years, which he called "Hades". Grigull based his work mainly on the orbits of comets whose orbits lay beyond the orbit of Neptune. There they could experience the gravitational influence of the body, which caused a noticeable deflection in the motion of Uranus. In 1921, Grigull revised the value of Hades' orbital period, since 310-330 years was more appropriate to explain the observed deviations.
In 1900, Hans-Emil Lau of Copenhagen published the orbital elements of two trans-Neptune planets at a distance of 46.6 and 70.7 AU, with masses 9 and 47.2 times that of Earth and about 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 Dalle concluded that a hypothetical planet existed 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 1900. In the same year, Theodore Grigull deduced the longitude of the trans-Neptune planet, which was less than 6 degrees different from the value for the planet Dalle, and later the difference decreased to 2.5 degrees. It was assumed that this planet is at a distance of 50.6 AU.
In 1904, Thomas Jefferson proposed the existence of three trans-Neptunian planets with semiaxes 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 suggested four hypothetical planets, but was unable to substantiate some details regarding their position and movements.
Two particularly elaborate predictions for trans-Neptune 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 Trans-Neptune Planets. Percival Lowell (Lynn, Mass 1915). They were interested in the same question, but they used different approximations and got different results.
Pickering used graphical analysis and assumed that "Planet O" is 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 magnitudes. Pickering, over the next 24 years, suggested eight other trans-Neptunian planets. Pickering's results were the reason for Galiot to correct the distances to his two trans-Neptune planets at 44 and 66 AU. and changes in their masses by 5 and 24 Earth masses, respectively.
In total, during the period from 1908 to 1932, Pickering suggested seven hypothetical planets - O, P, Q, R, S, T and U. The final values of the orbital elements for the planets O and P determined 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, as some curiosities. In 1911, Pickering suggested that planet Q has a mass of 20,000 Earth masses, making it 63 times more massive than Jupiter, or about 1/6 the mass of the Sun, which is closer to a star with a minimum mass than a planet. In addition, for this planet (Q), Pickering predicted a very elliptical orbit.
In the following 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 at 20 Earth masses and a magnitude of about 11 magnitude. 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 orbit of 1911. He assumed the 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 value of Planet X Lowell - 47.5 AU), a period of 336 years, a mass of 5 Earth masses, a stellar magnitude of 15 m. In 1929, Pickering assumed the planet U, at a distance of 5.79 AU, with a period of 13.93 years, inside Jupiter's orbit. Its mass was about 0.045 Earth masses, its eccentricity was 0.26. The last of the planets assumed by Pickering was the planet T, which he predicted in 1931: semiaxis 32.8 AU, a period of 188 years.
Orbital elements of planet O in different years:
Year Average Period Mass Sv. Node Tilt Longitude distance (years) (Earth masses) orbits 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 a propagandist for Mars canals, built a private observatory 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 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: for the epoch 1850-01-01, mean longitude was 11.67 degrees, perigee longitude 186 , eccentricity 0.228, average distance 47.5 AU from the Sun, longitude of the ascending node 110.99 degrees, orbital inclination 7.30 degrees, planet mass 1/21000 solar mass. Lowell and other astronomers searched in vain for Planet X in 1913-1915. In 1915, Lowell published his theoretical results for Planet X. Ironically, in the same year 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. On about 1000 plates with images that he received during the second search attempt, 515 asteroids, 700 different stars and 2 images of Pluto were subsequently discovered!
The third attempt to find Planet X began in April 1927. During the years 1927-1928, no progress was made. In December 1929, a young farmer and amateur astronomer from Kansas, Clyde Tombaugh, was invited to conduct the search. Tombaugh began work in April 1929. On January 23 and 29 of this year, Tombaugh photographed several photographic plates on which he found Pluto, on February 18 during their study. 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 called Pluto, turned out to be disappointingly small, with a mass of probably one Earth's 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 Earth's mass!). Planet X should, if, of course, it is she who is the cause of the disturbances in the orbit of Uranus, be much larger than this! Tombaugh continued his search for another 13 years and explored the sky from the northern celestial pole to a southern declination of 50 degrees, reaching in his search up to 16-17, and sometimes even 18 magnitudes. Tombaugh examined about 90 million images of nearly 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 1,800 galaxies and several small galaxy clusters, one new comet, about 775 new asteroids - but no more new planets other than Pluto. Tombaugh concluded that unknown planets brighter than 16.5 magnitude do not exist - only planets in almost polar orbits or located close to the southern celestial pole might not have entered the field of his research and not be discovered. He hoped to find a Neptune-sized planet at a distance of seven times Pluto or a Pluto-sized planet at 60 AU.
Giving Pluto its name constitutes a separate story. The first suggested 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 calling the planet Zeus, but later changed her mind to Constance. Many suggested calling 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 proposed 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 as to whether this was the very 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 Planet X Lowell, Planet O Pickering, 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) [unpredicted] 100 109.4 W (longitude perihelion) 204.9 280.1 223.4 T (date of perihelion) Feb. Jan 1991 2129 Sep 1989 u (annual motion) 1.2411 0.880 1.451 P (period, years) 282 409.1 248 T (date of perigation) 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 magnitude) 12-13 15 15
Pluto's mass was very difficult to determine. Several meanings 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 its mass. our moon! This made Pluto completely unsuitable for exerting an appreciable 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 appeared to be a triumph of celestial mechanics was actually a fluke, or rather the result of Clyde Tombaugh's elaborate quest.
Pluto's mass:
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-Neptune planet was reported on April 22, 1930 by R.M. Stewart from Ottawa (Canada) - it was discovered in pictures taken in 1924. Crommelin calculated its orbit (distance 39.82 AU, elevation node 280.49 degrees, orbit 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 also predicted new planets based on theoretical considerations (Lowell himself had already predicted a second trans-Neptune planet at a distance of about 75 AU). In 1946, Francis M.E. Sevin suggested the existence of a trans-Pluto planet at a distance of 78 AU. He drew this conclusion on the basis of 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 the logarithms of the periods of each pair of planets, getting an approximately constant sum of about 7.34. Assuming that the same amount will be given by a pair from Mercury and trans-Pluto, he received a period of about 677 years for "Transpluton". Later, Sevin calculated the full set of Transpluton's orbital elements: a distance of 77.8 AU, a period of 685.8 years, an eccentricity of 0.3, and a mass of 11.6 Earth masses. His prediction did not generate much interest among astronomers.
In 1950, K. Schutte from Munich used data from eight periodic comets to predict a trans-Pluto planet at 77 AU. Four years later, HHKitzinger from Karlsruhe, using the same comets, expanded and refined 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: a distance of 75.1 AU, a period of 650 years, an inclination angle of 40 degrees, a magnitude of 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 angle of inclination is 38 degrees, the eccentricity is 0.07, i.e. the planet is not the same as "Transpluton" Sevin, but more similar in some parameters to the last Planet P of Pickering. However, no such planet has been discovered.
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 is located at a distance of 36.2 AU. from the Sun or 1 AU from the aphelion of Halley's comet should delay the moment of its perihelion passage, which is in good agreement with observations. The planet is 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 of 120 degrees (i.e. in a retrograde orbit), with a magnitude of about 13-14, about the size of Saturn. Such a trans-plutonic planet would slow Halley's comet at the 1456th perihelion pass. This giant trans-Pluto planet was also searched for but never 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 orbital period, but not on the previous revolution. In 1976, Tom van Flandern became convinced that this was caused by the tenth planet. After the discovery of Charon in 1978, which showed that Pluto's mass was actually much less than expected, van Flandern convinced his USNO colleague Robert S. Harrington that a tenth planet existed. They began to collaborate on researching the satellite system of Neptune. Soon their views diverged. Van Flandern believed that the tenth planet formed beyond the orbit of Neptune, while Harrington believed that it happened in the orbits of Uranus and Neptune. Van Flandern believed more data was needed, such as an updated mass of Neptune from Voyager 2. Harrington, on the other hand, began his search for a planet with superhuman 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 magnitudes, (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 the order of 45 degrees, as an alternative to the "Nemesis" hypothesis. However, according to Eugene M. Shoemaker, this planet could not have been the cause of the meteor shower suggested by Whitmeer and Mates (see below).
In 1987, John Anderson of JPL tested the motions of the Pioneer 10 and Pioneer 11 spacecraft to see if their motions would be deflected by gravitational forces from unknown bodies. Nothing was found - from this Anderson concluded that the tenth planet most likely exists! JPL excluded from its calculation of its ephemeris observations of Uranus prior to 1910, 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 tilt. Its influence on the inner planets will not be detected again until at least 2600. Anderson hoped 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 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 has an orbit stabilized by mutual resonance with its closest neighbors, despite their great distance from each other. The decision 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 Powell planet should be in the constellation Leo and have a magnitude of about 12 magnitude. However, Powell himself thinks that these data are too premature for the search for a planet and need additional verification.
Even if trans-Pluto planets are never found, the outer parts of the 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 objects in the solar system using the 48-inch Schmidt camera of the Palomar Observatory. 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, 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 is 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 immediately designated as an asteroid. However, Koval suspected that this body may very much resemble a comet, and later it even acquired a short cometary tail! In 1995, Chiron was also classified as a comet - of course the largest comet we know of anything about.
In 1992, another distant asteroid was discovered: Pholus. Later in 1992, an asteroid was discovered beyond Pluto's orbit, followed by five more trans-Pluto asteroids discovered in 1993 and finally over ten more in 1994!
However, the spacecraft Pioneer 10 and 11, Voyager 1 and 2, 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 found. Voyagers also set more accurate masses for the outer planets - when this updated data was used to numerically integrate the motions in the solar system, all disagreements over the positions of the outer planets finally disappeared. It seems that the search for Planet X has finally come to an end. "Planet X" did not exist (Pluto does not really count), but instead an asteroid belt was discovered beyond the orbits of Neptune and Pluto! Asteroids beyond Jupiter's orbit, which were discovered in August 1993, are presented below:
Asteroid a e Tilt. Exc. Arg perig. Wednesday Period Name a.u. 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-Neptune asteroids were discovered:
Object a e tilt R Sound Diam. Opener au was discovered. hail. km Date 1992 QB1 43.9 0.070 2.2 22.8 283 Aug 1992 Jewitt & Luu 1993 FW 43.9 0.047 7.7 22.8 286 Mar 1993 Jewitt & Luu 1993 RO 39.3 0.198 3.7 23.2 139 Sep 1993 Jewitt & Luu 1993 RP 39.3 0.114 2.6 24.5 96 Sep 1993 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 1994 Oct Jewitt & Chen 1994 TG 42.3 0.000 6.8 23.0 232 1994 Oct 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. 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-Neptune bodies are divided into two groups. One group, consisting of Pluto, 1993 SC, 1993 SB and 1993 RO, has eccentric orbits and is in 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 the present
Let's assume that our Sun is not a single star, but has a companion. Suppose this companion star is in an elliptical orbit, with its distance from the Sun varying between 90,000 AU. (1.4 light years) and 20,000 AU, with a period of 30 million years. Let's also assume that this star is dark, or at least very faint, and therefore we have not noticed it before.This should mean that once every 30 million years, this hypothetical companion star to the Sun must pass through the Oort cloud (a hypothetical cloud of proto-comets that is very far from the Sun). During this passage, the proto-comets in the Oort cloud will "churn" around this star. 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 strongly, then the Earth runs the risk of colliding with the nucleus of one of them.
When studying 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 things. The most famous of these is, of course, the extinction of the dinosaurs about 65 million years ago. According to this hypothesis, about 15 million years from today, the time will come for the next mass extinction of life.
The "deadly companion" hypothesis of the Sun was put forward in 1985 by Daniel. Whitemyer (Daniel P. Whitmire) and John D. Matese (John J. Matese) from the University of South Louisiana (USA). This star even got a name: Nemesis... The only unpleasant moment with this hypothesis is that there is no indication at all of the existence of a companion star to the Sun. It needs to be very bright or massive, even a star is 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 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, 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, 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 the myth. If an anthropologist of the previous generation had heard such a story from his informants, then finishing writing it down in his next volume of academic works, he would undoubtedly use words such as "primitive" or "pre-scientific." 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 Sun-Demon 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 he will attack again. This is why some scientists, when they first heard it, thought that the theory of Nemesis was just a joke - the invisible Sun attacking the Earth along with comets, it sounds like a delusion or a myth. For this reason, many joked skeptically: we are always in danger of deceiving ourselves. But even if this theory has no weighty foundation, it is still serious and quite admissible, since its main 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
(Sorry, but all links provided by the author are from 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", 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
Quoted1>> Moons of Mercury
Do you have Mercury satellites: description of the first planet from the Sun with a photo, features of the orbit, history of the formation of the planet and moons in space, Hill's sphere.
You may have noticed that almost every planet in the solar system has satellites. And Jupiter has as many as 67! Even Pluto, offended by everyone, has five. And what about the first planet from the Sun? How many satellites does Mercury have and are there any?
Does Mercury have satellites
If satellites are quite common, then why is this planet devoid of such happiness? To understand the reason, you need to understand the principles of the formation of moons and see how this relates to the situation on Mercury.
Making natural moons
First of all, the satellite is capable of using material from the circumplanetary disk to form. Then all the fragments gradually combine and create large bodies that are able to acquire a spherical shape. Jupiter, Uranus, Saturn and Neptune followed a similar scenario.
The second way is to attract to yourself. Large bodies are able to act by gravity and attract other objects to themselves. This could have happened with the Martian moons Phobos and Deimos, as well as with small moons near the gas and ice giants. There is even an idea that Neptune's large moon Triton was previously considered a trans-Neptune object.
And the last one is a violent collision. At the time of the formation of the solar system, planets and other objects tried to find their place and often collided. This would cause the planets to eject a huge amount of material into space. It is believed that this is how the Earth's moon appeared about 4.5 billion years ago.
Hill's sphere
Hill's Sphere is the area around a celestial body that dominates the sun's gravity. Zero speed is observed at the outer edge. The object is not capable of overstepping this line. To acquire a moon, you need to place an object within this zone.
That is, all bodies in the Hill sphere are subject to the influence of the planet. If they are outside the line, then they obey our star. This also applies to the Earth, which holds the Moon. But Mercury has no satellites. In fact, it is unable to capture or shape its own moon. There are several reasons for this.
Size and orbit
Mercury is the smallest planet in the solar system, which was not lucky to be located very first, so its gravity is simply not enough to hold its satellite. Moreover, if a large object passed into the Hill's sphere, it would rather fall under the influence of the sun.
In addition, there is simply not enough material on the planet's orbital path to create a moon. Perhaps the reason is in stellar winds and condensation radii of light materials. At the time of the formation of the system, elements like methane and hydrogen remained in the form of gas near the star, and the heavy ones merged into terrestrial planets.
However, in the 1970s. still hoped that there might be a satellite. Mariner 10 captured a huge amount of UV rays, hinting at a large object. But the radiation was gone the next day. It turned out that the device caught signals from a distant star.
Unfortunately, Venus and Mercury have to while away the century alone, since in the solar system these are the only planets that do not have satellites. We are fortunate enough to be located at an ideal distance and possess a large Hill sphere. And let's thank the mysterious object that crashed into us in the past and spawned the moon!