The solar system is a group of planets revolving in specific orbits around a bright star - the Sun. This star is the main source of heat and light in the solar system.
It is believed that our planetary system was formed as a result of the explosion of one or more stars and this happened about 4.5 billion years ago. At first, the Solar System was an accumulation of gas and dust particles, however, over time and under the influence of its own mass, the Sun and other planets arose.
Planets of the Solar System
At the center of the solar system is the Sun, around which eight planets move in their orbits: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Until 2006, Pluto also belonged to this group of planets; it was considered the 9th planet from the Sun, however, due to its significant distance from the Sun and small size, it was excluded from this list and called a dwarf planet. More precisely, it is one of several dwarf planets in the Kuiper belt.
All of the above planets are usually divided into two large groups: the terrestrial group and the gas giants.
The terrestrial group includes such planets as: Mercury, Venus, Earth, Mars. They are distinguished by their small size and rocky surface, and in addition, they are located closest to the Sun.
Gas giants include: Jupiter, Saturn, Uranus, Neptune. They are characterized by large sizes and the presence of rings, which are ice dust and rocky pieces. These planets consist mainly of gas.
Sun
The Sun is the star around which all the planets and satellites in the solar system revolve. It consists of hydrogen and helium. The age of the Sun is 4.5 billion years, it is only in the middle of its life cycle, gradually increasing in size. Now the diameter of the Sun is 1,391,400 km. In just the same number of years, this star will expand and reach the orbit of the Earth.
The sun is the source of heat and light for our planet. Its activity increases or becomes weaker every 11 years.
Due to the extremely high temperatures on its surface, a detailed study of the Sun is extremely difficult, but attempts to launch a special device as close to the star as possible continue.
Terrestrial group of planets
Mercury
This planet is one of the smallest in the solar system, its diameter is 4,879 km. In addition, it is closest to the Sun. This proximity predetermined a significant temperature difference. The average temperature on Mercury during the day is +350 degrees Celsius, and at night - -170 degrees.
If we take the Earth year as a guide, Mercury makes a full revolution around the Sun in 88 days, and one day there lasts 59 Earth days. It was noticed that this planet can periodically change the speed of its rotation around the Sun, its distance from it and its position.
There is no atmosphere on Mercury; therefore, it is often attacked by asteroids and leaves behind a lot of craters on its surface. Sodium, helium, argon, hydrogen, and oxygen were discovered on this planet.
A detailed study of Mercury is very difficult due to its close proximity to the Sun. Sometimes Mercury can be seen from Earth with the naked eye.
According to one theory, it is believed that Mercury was previously a satellite of Venus, however, this assumption has not yet been proven. Mercury does not have its own satellite.
Venus
This planet is the second from the Sun. In size it is close to the diameter of the Earth, the diameter is 12,104 km. In all other respects, Venus differs significantly from our planet. A day here lasts 243 Earth days, and a year lasts 255 days. The atmosphere of Venus is 95% carbon dioxide, which creates a greenhouse effect on its surface. This results in an average temperature on the planet of 475 degrees Celsius. The atmosphere also contains 5% nitrogen and 0.1% oxygen.
Unlike the Earth, most of whose surface is covered with water, there is no liquid on Venus, and almost the entire surface is occupied by solidified basaltic lava. According to one theory, there used to be oceans on this planet, however, as a result of internal heating, they evaporated, and the vapors were carried away by the solar wind into outer space. Near the surface of Venus, weak winds blow, however, at an altitude of 50 km their speed increases significantly and amounts to 300 meters per second.
Venus has many craters and hills that resemble the earth's continents. The formation of craters is associated with the fact that the planet previously had a less dense atmosphere.
A distinctive feature of Venus is that, unlike other planets, its movement occurs not from west to east, but from east to west. It can be seen from Earth even without the help of a telescope after sunset or before sunrise. This is due to the ability of its atmosphere to reflect light well.
Venus has no satellite.
Earth
Our planet is located at a distance of 150 million km from the Sun, and this allows us to create on its surface a temperature suitable for the existence of liquid water, and, therefore, for the emergence of life.
Its surface is 70% covered with water, and it is the only planet to contain such an amount of liquid. It is believed that many thousands of years ago, steam contained in the atmosphere created the temperature on the Earth's surface necessary for the formation of water in liquid form, and solar radiation contributed to photosynthesis and the birth of life on the planet.
The peculiarity of our planet is that under the earth’s crust there are huge tectonic plates, which, moving, collide with each other and lead to changes in the landscape.
The diameter of the Earth is 12,742 km. An earthly day lasts 23 hours 56 minutes 4 seconds, and a year lasts 365 days 6 hours 9 minutes 10 seconds. Its atmosphere is 77% nitrogen, 21% oxygen and a small percentage of other gases. None of the atmospheres of other planets in the solar system has such an amount of oxygen.
According to scientists, the age of the Earth is 4.5 billion years, approximately the same age that its only satellite, the Moon, has existed. It is always turned to our planet with only one side. There are many craters, mountains and plains on the surface of the Moon. It reflects sunlight very weakly, so it is visible from Earth in the pale moonlight.
Mars
This planet is the fourth from the Sun and is 1.5 times more distant from it than the Earth. The diameter of Mars is smaller than Earth's and is 6,779 km. The average air temperature on the planet ranges from -155 degrees to +20 degrees at the equator. The magnetic field on Mars is much weaker than that of Earth, and the atmosphere is quite thin, which allows solar radiation to unimpededly affect the surface. In this regard, if there is life on Mars, it is not on the surface.
When surveyed with the help of Mars rovers, it was found that there are many mountains on Mars, as well as dried up river beds and glaciers. The surface of the planet is covered with red sand. It is iron oxide that gives Mars its color.
One of the most frequent events on the planet are dust storms, which are voluminous and destructive. It was not possible to detect geological activity on Mars, however, it is reliably known that significant geological events previously occurred on the planet.
The atmosphere of Mars consists of 96% carbon dioxide, 2.7% nitrogen and 1.6% argon. Oxygen and water vapor are present in minimal quantities.
A day on Mars is similar in length to those on Earth and is 24 hours 37 minutes 23 seconds. A year on the planet lasts twice as long as on Earth - 687 days.
The planet has two satellites Phobos and Deimos. They are small in size and uneven in shape, reminiscent of asteroids.
Sometimes Mars is also visible from Earth with the naked eye.
Gas giants
Jupiter
This planet is the largest in the solar system and has a diameter of 139,822 km, which is 19 times larger than Earth. A day on Jupiter lasts 10 hours, and a year is approximately 12 Earth years. Jupiter is mainly composed of xenon, argon and krypton. If it were 60 times larger, it could become a star due to a spontaneous thermonuclear reaction.
The average temperature on the planet is -150 degrees Celsius. The atmosphere consists of hydrogen and helium. There is no oxygen or water on its surface. There is an assumption that there is ice in the atmosphere of Jupiter.
Jupiter has a huge number of satellites - 67. The largest of them are Io, Ganymede, Callisto and Europa. Ganymede is one of the largest moons in the Solar System. Its diameter is 2634 km, which is approximately the size of Mercury. In addition, a thick layer of ice can be seen on its surface, under which there may be water. Callisto is considered the most ancient of the satellites, since it is its surface that has the largest number of craters.
Saturn
This planet is the second largest in the solar system. Its diameter is 116,464 km. It is most similar in composition to the Sun. A year on this planet lasts quite a long time, almost 30 Earth years, and a day lasts 10.5 hours. The average surface temperature is -180 degrees.
Its atmosphere consists mainly of hydrogen and a small amount of helium. Thunderstorms and auroras often occur in its upper layers.
Saturn is unique in that it has 65 moons and several rings. The rings are made up of small particles of ice and rock formations. Ice dust perfectly reflects light, so Saturn's rings are very clearly visible through a telescope. However, it is not the only planet with a diadem; it is just less noticeable on other planets.
Uranus
Uranus is the third largest planet in the solar system and the seventh from the Sun. It has a diameter of 50,724 km. It is also called the “ice planet”, as the temperature on its surface is -224 degrees. A day on Uranus lasts 17 hours, and a year lasts 84 Earth years. Moreover, summer lasts as long as winter - 42 years. This natural phenomenon is due to the fact that the axis of that planet is located at an angle of 90 degrees to the orbit and it turns out that Uranus seems to be “lying on its side.”
Uranus has 27 moons. The most famous of them are: Oberon, Titania, Ariel, Miranda, Umbriel.
Neptune
Neptune is the eighth planet from the Sun. It is similar in composition and size to its neighbor Uranus. The diameter of this planet is 49,244 km. A day on Neptune lasts 16 hours, and a year is equal to 164 Earth years. Neptune is an ice giant and for a long time it was believed that no weather phenomena occur on its icy surface. However, it was recently discovered that Neptune has raging vortices and wind speeds that are the highest among the planets in the solar system. It reaches 700 km/h.
Neptune has 14 moons, the most famous of which is Triton. It is known to have its own atmosphere.
Neptune also has rings. This planet has 6 of them.
Interesting facts about the planets of the solar system
Compared to Jupiter, Mercury seems like a dot in the sky. These are the actual proportions in the solar system:
Venus is often called the Morning and Evening Star, since it is the first of the stars visible in the sky at sunset and the last to disappear from visibility at dawn.
An interesting fact about Mars is the fact that methane was found on it. Due to the thin atmosphere, it constantly evaporates, which means that the planet has a constant source of this gas. Such a source could be living organisms inside the planet.
There are no seasons on Jupiter. The biggest mystery is the so-called “Great Red Spot”. Its origin on the surface of the planet has not yet been fully elucidated. Scientists suggest that it was formed by a huge hurricane, which has been rotating at very high speed for several centuries.
An interesting fact is that Uranus, like many planets in the solar system, has its own ring system. Due to the fact that the particles that make up them do not reflect light well, the rings could not be detected immediately after the discovery of the planet.
Neptune has a rich blue color, so it was named after the ancient Roman god - the master of the seas. Due to its distant location, this planet was one of the last to be discovered. At the same time, its location was calculated mathematically, and after time it was able to be seen, and precisely in the calculated place.
Light from the Sun reaches the surface of our planet in 8 minutes.
The solar system, despite its long and careful study, still conceals many mysteries and secrets that have yet to be revealed. One of the most fascinating hypotheses is the assumption of the presence of life on other planets, the search for which is actively continuing.
Details Category: About the planets of the solar system Published 10/15/2012 15:55 Views: 24664
Most of the planets in the solar system were discovered in ancient times. Since then they have been observed regularly. Mercury, Venus, Mars, Jupiter and Saturn are visible to the naked eye, so it is impossible to say with certainty who and when first discovered them.
You can read more about the planets of the Solar System on our website: http://site/index.php/3-planeti-solnechnoy-sistemi.
The closest planet to the Sun is small Mercury. Its orbit is close to the Sun (on astronomical scales) - the average distance between Mercury and the Sun is “only” 57,900,000 km.
It is difficult to establish a date for the discovery of this planet, but the earliest known observation of Mercury was recorded in the collection Babylonian astronomical tables by Assyrian astronomers around the 14th century BC. uh. The Sumerian name can be read as "jumping planet." The planet was originally associated with the god Ninurta (the god of happy war), and in later records it is called "Nabu" after the god of wisdom and scribal arts.
In ancient Greece during Hesiod the planet was known under the names Στίλβων (“Stilbon”) and Ἑρμάων (“Hermaon”) - a form of the name of the god Hermes. Later the Greeks began to call the planet "Apollo".
There is an assumption that the name “Apollo” corresponded to visibility in the morning sky, and “Hermes” (“Hermaon”) in the evening sky. The Romans named the planet after the god of commerce, Mercury, who is equivalent to the Greek god Hermes, because he moves through the sky faster than the other planets. Claudius Ptolemy, in his work “Hypotheses about the Planets,” wrote about the possibility of a planet moving through the disk of the Sun. But such a transit has never been observed because a planet like Mercury is too small to observe or because the moment of transit occurs infrequently.
Mercury was observed and in Ancient China, there they called him Chen-hsing (辰星), “Morning Star”. The synodic period of Mercury was recognized by Chinese scientists as equal to 115.91 days. In modern Chinese, Korean, Japanese and Vietnamese cultures, the planet came to be called "Water Star" (水星).
In Indian mythology Mercury was called Budha. This god, the son of Soma, was dominant on Wednesdays. In Germanic paganism the god Odin was also associated with the planet Mercury and the environment. Mayan Indians Mercury was represented as an owl (or, perhaps, as four owls: two corresponded to the morning appearance of Mercury, and two to the evening), which was the messenger of the underworld. In Hebrew, Mercury was called "Kohav Hama" ("Solar Planet").
Medieval observations of Mercury in the northern parts of Europe were hampered by the fact that the planet is always observed at dawn - morning or evening - against the background of a twilight sky and quite low above the horizon (especially in northern latitudes). The period of its best visibility occurs several times a year (lasting about 10 days). Even during these periods, it is not easy to see Mercury with the naked eye (a relatively dim star against a fairly light background of the sky).
There is a well-known legend that Nicolaus Copernicus regretted that he had never seen Mercury in his entire life. Indeed, in Copernicus’s work “On the Rotations of the Celestial Spheres” there is not a single example of observations of Mercury. But he described the planet using the observations of other astronomers. As he himself said, Mercury can still be “caught” from northern latitudes by showing patience and cunning.
Mercury was seen for the first time through a telescope Galileo Galilei at the beginning of the 17th century, but his telescope was not powerful enough to observe the phases of Mercury. In 1631 Pierre Gassendi made the first telescopic observation of the passage of a planet across the disk of the Sun, but the moment of passage was calculated before that Johannes Kepler. In 1639 Giovanni Zupi using a telescope, he discovered that the orbital phases of Mercury are similar to the phases of the Moon and Venus - this finally confirmed that Mercury revolves around the Sun.
A very rare astronomical event is the overlap of one planet with the disk of another, observed from Earth. Venus overlaps Mercury once every few centuries, and this event has only been observed once in history - on May 28, 1737 John Bevis at the Royal Greenwich Observatory. Venus' next occultation of Mercury will be on December 3, 2133.
The difficulties accompanying the observation of Mercury have led to the fact that for a long time it was studied less than other planets.
The proximity of the Sun also creates some problems for the telescopic study of Mercury. For example, the Hubble telescope has never been used and will not be used to observe this planet. Its device does not allow observations of objects close to the Sun - if you try to do this, the equipment will suffer irreversible damage.
Mercury is the least studied terrestrial planet. In the 20th century, radio astronomy, radar and research using spacecraft were added to the telescopic methods of studying it.
Latest research data on Mercury:
Mercury's surface temperature: 600 K at the subsolar point and 150 K on the unlit side.
The reflective properties of Mercury and the Moon are similar.
Mercury's rotation period: 59 days.
In the picture you see Mariner 10, the first spacecraft to reach Mercury.
Two spacecraft were sent to study Mercury: Mariner 10 flew past Mercury three times in 1974-1975; the closest approach was 320 km. Several thousand images were taken. Further research from Earth showed the possibility of the existence of water ice in polar craters.
Of all the planets visible to the naked eye, only Mercury has never had its own artificial satellite. NASA is currently conducting a second mission to Mercury called Messenger. The device was launched on August 3, 2004, and in January 2008 it made its first flyby of Mercury. To enter orbit around the planet in 2011, the device performed two more gravity assist maneuvers near Mercury.
The European Space Agency (ESA), together with the Japan Aerospace Exploration Agency (JAXA), is developing the Bepi Colombo mission to explore the surface of Mercury and its depth, as well as observe the planet's magnetic field and magnetosphere. The launch of the device is planned for 2013.
More opportunities have emerged for ground-based observations of Mercury using CCD radiation receivers and subsequent computer processing of images. On March 17, 2011, the interplanetary probe Messenger entered Mercury orbit. According to the first studies, the planet's magnetic field is not symmetrical relative to the poles; Thus, different numbers of solar wind particles reach Mercury's north and south poles. An analysis of the prevalence of chemical elements on the planet was also carried out. Research continues.
Russia plans to send the first Mercury-P landing station to the planet. The project was planned for 2019, but was significantly delayed.
Venus was also observed in ancient times - it is easy to see in the sky, because in brilliance it far exceeds the brightest stars. For millennia, it has captivated people's gaze. The planet is named after the goddess of love. It has a smooth white color. Like Mercury, Venus has periods of morning and evening visibility, so in ancient times it was believed that morning and evening Venus were different stars. Using a telescope, you can easily observe changes in the visible phase of the planet's disk. I saw him for the first time in 1610 Galileo.
On Earth, you can observe the passage of Venus across the disk of the Sun, when from Earth through a telescope this planet is visible as a small black disk against the background of the huge Sun. For the first time, the passage of Venus across the disk of the Sun was observed by an English astronomer on December 4, 1639. Jeremiah Horrocks, but first he calculated this phenomenon.
“The appearance of Venus on the Sun” was observed by M. V. Lomonosov June 6, 1761. This phenomenon was observed all over the world, but only M.V. Lomonosov drew attention to the fact that when Venus came into contact with the disk of the Sun, a “thin, hair-like glow” appeared around the planet. The same light halo was observed during the descent of Venus from the solar disk. Thus, the presence of an atmosphere on Venus was discovered, and this was a hundred years before the discovery of spectral analysis!
Venus has been intensively studied by spacecraft. The first spacecraft intended to study Venus was the Soviet “Venera-1” (February 12, 1961), the Soviet spacecraft of the “Venera”, “Vega” series, the American “Mariner”, “Pioneer-Venera-1” series were sent to the planet. “Pioneer Venus 2”, “Magellan”, European “Venus Express”, Japanese “Akatsuki”. In 1975, the Venera-9 and Venera-10 spacecraft transmitted the first photographs of the surface of Venus to Earth. But the conditions on the surface of Venus are such that none of the spacecraft worked on the planet for more than two hours. Roscosmos plans to send the Venera-D station with a satellite of the planet and a more durable probe, which should work on the surface of the planet for at least a month.
The exploration of Mars also began a very long time ago - more than 3.5 thousand years ago in Ancient Egypt. The planet was named after Mars, the ancient Roman god of war (corresponding to the ancient Greek Ares). Mars is sometimes called the “red planet” because of the reddish tint of its surface given by iron oxide. Mars has moons Phobos and Deimos.
Descriptions of the position of Mars have been preserved, compiled by Babylonian astronomers, who developed a number of mathematical methods to predict the position of the planet. Using the data of the Egyptians and Babylonians, ancient Greek philosophers and astronomers developed a detailed geocentric model to explain the motion of the planets. Several centuries later Indian and Islamic astronomers Calculated the size of Mars and its distance from Earth. Johannes Kepler introduced a more accurate elliptical orbit of Mars, coinciding with the observed one.
In 1659 Francesco Fontana, examining Mars through a telescope, made the first drawing of the planet - in the form of a black spot.
In 1660, two polar caps were added to the black spot, added Jean Dominique Cassini.
In 1888 Giovanni Schiaparelli gave the first names to individual surface details: the seas of Aphrodite, Erythraean, Adriatic, Cimmerian; lakes Sun, Lunnoe and Phoenix.
The heyday of telescopic observations of Mars occurred at the end of the 19th - mid-20th centuries.
Since the 1960s, the exploration of Mars has been carried out by the USSR AMS (Mars and Phobos programs), ESA and the USA (Mariner, Viking, Mars Global Surveyor programs and others).
Currently, Mars is being actively explored. There are three actively operating spacecraft in Mars orbit:
"Mars Reconnaissance Satellite"
Mars Express with Marsis radar
"Mars Odysseus"
Rovers operating on the surface of the planet:
"Opportunity" (since January 25, 2004) as part of the Mars Exploration Rover program
Curiosity (since August 6, 2012) as part of the Mars Science Laboratory program.
Although Mars has been studied much better than other planets, it is still a mystery to us.
Jupiter
Together with Saturn, Uranus and Neptune, Jupiter is one of the gas giants. This planet has been known to people since ancient times, which is reflected in the mythology and religious beliefs of various cultures: Mesopotamian, Babylonian, Greek and others. The modern name of Jupiter comes from the name of the ancient Roman supreme god of thunder. Jupiter has natural satellites. To date, scientists know 67 satellites of Jupiter.
At the beginning of the 17th century Galileo Galilei studied Jupiter using a telescope he invented and discovered the four largest satellites of the planet. In the 1660s Giovanni Cassini observed spots and stripes on the “surface” of the giant. In 1671, observing the eclipses of the satellites of Jupiter, Danish astronomer Ole Roemer discovered that the true position of the satellites did not coincide with the calculated parameters, and the magnitude of the deviation depended on the distance to the Earth. Based on these observations, Roemer concluded that the speed of light is finite and established its value as 215,000 km/s (the modern value is 299,792.458 km/s).
Since the second half of the 20th century, Jupiter has been actively studied both with the help of ground-based telescopes (including radio telescopes) and with the help of spacecraft - the Hubble telescope and a number of probes. Since the 1970s, 8 interplanetary NASA probes have been sent to the planet: Pioneers, Voyagers, Galileo and others.
Jupiter has been studied exclusively by US NASA apparatus.
To the naked eye, Jupiter appears as a bright star. Because of its enormous size, even small telescopes can see faintly colored ribbons of clouds and a large red spot on its disk.
Gas giant. Named after the Roman god of agriculture. Saturn has a prominent ring system made up primarily of ice particles and smaller amounts of heavy elements and dust. Seeing Saturn for the first time through a telescope in 1609-1610, Galileo Galilei noticed that Saturn does not look like a single celestial body, but like three bodies almost touching each other, and suggested that these are two large “companions” (satellites) of Saturn. In 1633 Gassendi drew a bright ring around Saturn. In 1656 Huygens confirms that there is a thin, flat ring around Saturn that does not touch the planet. In 1675 Cassini discovers a gap in the rings, which is later called the Cassini gap, and Encke in 1837 g. finds the second gap. IN 1852 Lascelles establishes that Saturn's ring is almost transparent, which means it cannot be solid. In addition, he suggested that this ring consists of individual particles located very close to each other, so they appear to be a continuous ribbon. In 1895 Keeler finds that individual parts of the rings rotate at different speeds, and this also confirms Lascelles' assumption that the rings cannot be solid.
Saturn has 62 known natural satellites with confirmed orbits, 53 of which have their own names. Most of the satellites are small in size and consist of rocks and ice.
Huygens also discovered Saturn's largest moon, Titan. There were no further significant discoveries until 1789, when W. Herschel discovered two more satellites - Mimas and Enceladus. Then a group of British astronomers discovered the satellite Hyperion, with a shape very different from spherical. In 1899, William Pickering discovered Phoebe, which belongs to the class of irregular satellites and does not rotate synchronously with Saturn like most satellites. The period of its revolution around the planet is more than 500 days, while the revolution goes in the opposite direction. In 1944 by Gerard Kuiper The presence of a powerful atmosphere on another satellite, Titan, was discovered. This phenomenon is unique for the satellite in the Solar System. In the 1990s, Saturn, its moons and rings were repeatedly studied by the Hubble Space Telescope.
Saturn is being explored by the automatic interplanetary stations (AIS) Cassini-Huygens, Voyager (program), and Pioneer 11. In 2009, a joint American-European project between NASA and ESA appeared to launch the Titan Saturn System Mission to study Saturn and its satellites Titan and Enceladus. During it, the station will fly to the Saturn system for 7-8 years, and then become a satellite of Titan for two years. It will also launch a probe balloon into Titan’s atmosphere and a landing module (possibly floating).
The planet is visible from Earth with the naked eye.
Uranium was discovered March 13, 1781 by English astronomer William Herschel. While studying the starry sky through his telescope, he noticed that Uranus was moving relative to the stars. Other people had seen Uranus before, even marked it on star charts, but they did not realize that it was not a star.
Outside the orbit of Saturn there are two planets that have much in common - Uranus and Neptune. Uranus has 27 known natural satellites.
The planet is named after the Greek god of the sky. Uranus is 19 times farther from the Sun than Earth. Uranus's orbital journey lasts more than 84 years. When Uranus is at its brightest, it can be seen with the naked eye as a star. Uranus stands out among other planets in that it makes its way in orbit around the Sun on its side. Maybe it collided with some celestial body and capsized? Uranus also has rings, they were discovered in 1977. True, they are faintly visible.
Uranus is being explored by NASA's Voyager 2 spacecraft and the Hubble Space Telescope.
Neptune is the eighth and outermost planet in the solar system. The planet was named after the Roman god of the seas.
Based on small deviations in the orbit of Uranus, John Adams and Urbain Le Verrier predicted the existence of another, more distant planet. September 23, 1846 at the request of Le Verrier Johann Halle found a new planet - Neptune.
Many people have seen Neptune before, including Galileo Galilei, who, while observing Jupiter, noticed a "star" now believed to be Neptune. Neptune was the first planet discovered through mathematical calculations rather than through regular observations.
Neptune has natural satellites, as well as a fragmented ring system, discovered back in the 1960s, but only reliably confirmed by Voyager 2 in 1989. Triton is an amazing satellite of Neptune; it moves in orbit in the opposite direction relative to Neptune.
Voyager 2 explores Neptune. Voyager 2 came closest to Neptune on August 25, 1989. It turned out that Neptune is one of the most beautiful planets in the solar system.
The most distant planet in our solar system is Pluto. She was discovered February 18, 1930 by American astronomer Clyde Tombaugh. He photographed the same part of the night sky on different days, as a result of which he discovered an object moving relative to the stars. Further observations showed that this object is a planet.
However, there is serious disagreement on this issue. Pluto doesn't behave like a planet. Pluto's elongated orbit is more like that of a comet. Because Pluto is so far away, it is difficult to see. Even in the most powerful telescopes it is visible as a tiny circle. But observations made using advanced technology suggest that Pluto is similar to Neptune's moon Triton. Pluto was initially classified as a planet, but is now considered one of the largest objects (perhaps the largest) in the Kuiper Belt.
In January 2016, scientists announced that there may be another planet in the solar system. Many astronomers are looking for it; research so far has led to ambiguous conclusions. Nevertheless, the discoverers of Planet X are confident of its existence. talks about the latest results of work in this direction.
About the possible detection of Planet X beyond the orbit of Pluto, astronomers and Konstantin Batygin from the California Institute of Technology (USA). The ninth planet of the solar system, if it exists, is about 10 times heavier than the Earth, and its properties resemble Neptune - a gas giant, the most distant of the known planets orbiting our star.
According to the authors' estimates, the period of Planet X's revolution around the Sun is 15 thousand years, its orbit is highly elongated and inclined relative to the plane of the Earth's orbit. The maximum distance from the Sun of Planet X is estimated at 600-1200 astronomical units, which takes its orbit beyond the Kuiper belt, in which Pluto is located. The origin of Planet X is unknown, but Brown and Batygin believe that this cosmic object was knocked out of a protoplanetary disk near the Sun 4.5 billion years ago.
Astronomers discovered this planet theoretically by analyzing the gravitational disturbance it exerts on other celestial bodies in the Kuiper belt - the trajectories of six large trans-Neptunian objects (that is, located beyond the orbit of Neptune) were combined into one cluster (with similar perihelion arguments, longitude of the ascending node and inclination). Brown and Batygin initially estimated the probability of error in their calculations at 0.007 percent.
Where exactly Planet X is located is unknown, what part of the celestial sphere should be tracked by telescopes is unclear. The celestial body is located so far from the Sun that it is extremely difficult to notice its radiation with modern means. And the evidence for the existence of Planet X, based on the gravitational influence it exerts on celestial bodies in the Kuiper belt, is only indirect.
Video: caltech / YouTube
In June 2017, astronomers from Canada, Great Britain, Taiwan, Slovakia, the USA and France searched for Planet X using the OSSOS (Outer Solar System Origins Survey) catalog of trans-Neptunian objects. The orbital elements of eight trans-Neptunian objects were studied, the movement of which would have been influenced by Planet X - the objects would have been grouped in a certain way (clustered) according to their inclinations. Among the eight objects, four were examined for the first time; all of them are located at a distance of more than 250 astronomical units from the Sun. It turned out that the parameters of one object, 2015 GT50, did not fit into clustering, which cast doubt on the existence of Planet X.
However, the discoverers of Planet X believe that the 2015 GT50 does not contradict their calculations. As Batygin noted, numerical simulations of the dynamics of the Solar System, including Planet X, show that beyond the semi-major axis of 250 astronomical units there should be two clusters of celestial bodies whose orbits are aligned with Planet X: one stable, the other metastable. Although the 2015 GT50 is not included in any of these clusters, it is still reproduced by the simulation.
Batygin believes that there may be several such objects. The position of the minor semi-axis of Planet X is probably connected with them. The astronomer emphasizes that since the publication of data about Planet X, not six, but 13 trans-Neptunian objects indicate its existence, of which 10 celestial bodies belong to the stable cluster.
While some astronomers doubt Planet X, others are finding new evidence in its favor. Spanish scientists Carlos and Raul de la Fuente Marcos studied the parameters of the orbits of comets and asteroids in the Kuiper belt. The discovered anomalies in the movement of objects (correlations between the longitude of the ascending node and inclination) are easily explained, according to the authors, by the presence in the Solar System of a massive body whose orbital semi-major axis is 300-400 astronomical units.
Moreover, there may be not nine, but ten planets in the solar system. Recently, astronomers from the University of Arizona (USA) discovered the existence of another celestial body in the Kuiper belt, with a size and mass close to Mars. Calculations show that the hypothetical tenth planet is distant from the star at a distance of 50 astronomical units, and its orbit is inclined to the ecliptic plane by eight degrees. The celestial body disturbs known objects from the Kuiper belt and, most likely, was closer to the Sun in ancient times. Experts note that the observed effects are not explained by the influence of Planet X, located much further than the “second Mars.”
Currently, about two thousand trans-Neptunian objects are known. With the introduction of new observatories, in particular LSST (Large Synoptic Survey Telescope) and JWST (James Webb Space Telescope), scientists plan to increase the number of known objects in the Kuiper belt and beyond to 40 thousand. This will make it possible not only to determine the exact parameters of the trajectories of trans-Neptunian objects and, as a result, to indirectly prove (or disprove) the existence of Planet X and the “second Mars”, but also to directly detect them.