How many planets are internal? The planets of our solar system with you. Brief information about the planets of the solar system
solar system- these are 8 planets and more than 63 of their satellites, which are opening more and more often, several dozen comets and a large number of asteroids. All cosmic bodies move along their clear directed trajectories around the Sun, which is 1000 times heavier than all bodies in the solar system put together. The center of the solar system is the Sun - the star around which the planets revolve in orbits. They do not emit heat and do not glow, but only reflect the light of the Sun. There are now 8 officially recognized planets in the solar system. Briefly, in order of distance from the sun, we list them all. And now there are a few definitions.
Planet Is a celestial body that must satisfy four conditions:
1.the body must revolve around the star (for example, around the sun);
2. the body must have sufficient gravity to be spherical or close to it;
3. the body should not have other large bodies near its orbit;
4.the body shouldn't be a star
Satellites of the planets. The solar system also includes the Moon and natural satellites of other planets, which all of them have, except for Mercury and Venus. More than 60 satellites are known. Most of the satellites of the outer planets were discovered when they received photographs taken by robotic spacecraft. The smallest satellite of Jupiter - Leda - is only 10 km across.
Is a star, without which life on Earth could not exist. She gives us energy and warmth. According to the classification of stars, the Sun is a yellow dwarf. Age about 5 billion years. It has a diameter at the equator equal to 1,392,000 km, 109 times larger than the Earth. The rotation period at the equator is 25.4 days and 34 days at the poles. The mass of the Sun is 2x10 to the 27th power of tons, about 332950 times the mass of the Earth. The temperature inside the core is about 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius. In terms of chemical composition, the Sun consists of 75% hydrogen, and of the other 25% of the elements, most of all helium. Now, in order, let's figure out how many planets revolve around the sun, in the solar system and the characteristics of the planets.
The four inner planets (closest to the Sun) - Mercury, Venus, Earth and Mars - have a solid surface. They are smaller than four giant planets. Mercury moves faster than other planets, burning sunbeams during the day and freezing at night.
The period of revolution around the Sun: 87.97 days. Diameter at the equator: 4878 km.
Rotation period (revolution around the axis): 58 days.
Surface temperature: 350 during the day and -170 at night.
Atmosphere: very thin, helium.
How many satellites: 0.
The main satellites of the planet: 0.
More like Earth in size and brightness. Observing her is difficult because of the clouds that envelop her. The surface is a hot rocky desert. 
The period of revolution around the Sun: 224.7 days.
Diameter at the equator: 12104 km.
Rotation period (revolution around the axis): 243 days.
Surface temperature: 480 degrees (average).
Atmosphere: dense, mainly carbon dioxide.
How many satellites: 0.
The main satellites of the planet: 0.
Apparently, the Earth was formed from a gas and dust cloud, like other planets. Particles of gas and dust, colliding, gradually "grew" the planet. Surface temperatures reached 5,000 degrees Celsius. Then the Earth cooled down and was covered with hard stone crust. But the temperature in the bowels is still quite high - 4500 degrees. Rocks in the bowels are melted and, during volcanic eruptions, are poured onto the surface. Only on earth there is water. That is why life exists here. It is located relatively close to the Sun in order to receive the necessary heat and light, but far enough so as not to burn out.
The period of revolution around the Sun: 365.3 days. Diameter at equator: 12756 km.
The period of the planet's rotation (revolution around the axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: Mainly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.
Due to the resemblance to Earth, it was believed that life exists here. But descended to the surface of Mars spacecraft I did not find any signs of life. This is the fourth planet in order. 
The period of revolution around the Sun: 687 days.
Diameter of the planet at the equator: 6794 km
Rotation period (revolution around the axis): 24 hours 37 minutes.
Surface temperature: –23 degrees (average).
Atmosphere of the planet: thin, mostly carbon dioxide.
How many satellites: 2.
The main satellites in order: Phobos, Deimos.
Jupiter, Saturn, Uranus and Neptune are composed of hydrogen and other gases. Jupiter is more than 10 times larger than Earth in diameter, 300 times in mass, and 1300 times in volume. It is more than twice as massive as all the planets. Solar system put together. How long does it take for the planet Jupiter to become a star? It is necessary to increase its mass by 75 times!
The period of revolution around the Sun: 11 years 314 days. Diameter of the planet at the equator: 143884 km
Rotation period (revolution around the axis): 9 hours 55 minutes.
The planet's surface temperature is –150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.
It is the number 2 largest planet in the solar system. Saturn is eye-catching thanks to its ring system made of ice, rocks and dust that orbits the planet. There are three main rings with an outer diameter of 270,000 km, but their thickness is about 30 meters. 
The period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (revolution around the axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.
Unique planet in the solar system. Its peculiarity is that it does not revolve around the Sun like everyone else, but "lying on its side". Uranus also has rings, although they are more difficult to see. In 1986, Voyager-2 flew at a distance of 64,000 km, he had six hours of photography, which he successfully implemented.
Circulation period: 84 years 4 days. Diameter at the equator: 51,118 km.
The period of the planet's rotation (revolution around the axis): 17 hours 14 minutes.
Surface temperature: –214 degrees (average).
Atmosphere: Mainly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.
On this moment, Neptune is considered the last planet of the solar system. Its discovery took place by means of mathematical calculations, and then they saw it through a telescope. In 1989, Voyager 2 flew by. He took striking photographs of the blue surface of Neptune and its largest moon, Triton. 
The period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Period of rotation (revolution around the axis): 16 hours 7 minutes.
Surface temperature: –220 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 8.
Main satellites: Triton.
On August 24, 2006, Pluto lost its planetary status. The International Astronomical Union has decided which celestial body should be considered a planet. Pluto does not meet the requirements of the new formulation and loses its "planetary status", at the same time Pluto passes into a new quality and becomes the prototype of a separate class of dwarf planets.
How the planets appeared. Approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy ( Milky way), which has the shape of a disk, began to shrink towards the center, gradually forming the current Sun. Further, according to one of the theories, under the influence of powerful forces of attraction, a large number of dust and gas particles revolving around the Sun began to stick together into balls - forming future planets. According to another theory, the gas-dust cloud immediately disintegrated into separate clusters of particles, which were compressed and compressed, forming the current planets. Now 8 planets revolve around the Sun constantly.
solar system
According to scientific hypothesis, our system was formed from a dark gas and dust cloud 4.6 billion years ago. As a result of powerful transformations, the cloud turned into a young system with a central yellow star, planets, asteroids and various space bodies.
The structure of the solar system
Our system includes a star of average brightness - the Sun, and 8 classical planets that revolve around it in elliptical orbits at different distances. It is noteworthy that up to 2006, there were 9 planets in the system, the last was Pluto. However, due to new discoveries, Pluto was reclassified, and as a result, it acquired the status of a dwarf planet along with Ceres, Eris and other similar objects.
K, Pluto has a moon Charon, which is half the size of a dwarf planet. Further reclassification of Pluto into a binary planet is being considered, but today there is not enough information about the structure of the cosmos for such a classification.
The inner and outer planets are separated by an asteroid belt.
What are the inner planets
The planets of the system are divided into small warm (internal) and cold gas supergiants (external). The first type includes Mercury, Venus, Mars and Earth. Outside - Yuriter, Saturn, Uranus, Neptune. The inner planets have a solid core and are composed of metals, gases (oxygen, hydrogen and others), and other heavy elements. The largest are Earth and Venus with sizes of 1 and 0.81, respectively. Earth and Mars have satellites. In particular, the "blue" planet has the Moon, the "red" planet has Phobos and Deimos, which translates as "fear" and "horror". This name of the satellites of Mars is due to the fact that the object was named after the god of war Mars (aka Ares).
The inner planets are much smaller than the gas giants.
The inner and outer planets are separated by a wide asteroid belt that stretches between Mars and Jupiter. Unlike gas giants, solid planets do not have rings of asteroid debris, gas and dust. The smallest Uranus is 14 times larger than the largest "warm" planet - Earth.
In the scientific world, it is believed that on planets like Earth, the possibility of the occurrence or presence of life is higher than on gas giants. Largely due to the favorable climate and internal structure of such planets. In this regard, the search for such space objects is receiving increased attention from astronomers and scientists.
Questions:1. How is the name "wandering stars" translated from Greek?
2. Name the inner planets.
3. Which planets are external?
Planet - solid or solid and gas that revolve around the star.Even the ancient people in the sky noticed constantly moving stars, and the Greeks called them that. "wandering stars" that is, in Greek "planets".
There are nine planets in the solar system: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, Jupiter, Pluto.
Inner planets- Mercury, Mars, Venus, Earth.
The planets belonging to this group are small in size and mass, the average density of these planets is several times higher than the density of water; they slowly revolve around their axes; they have few satellites ( Mercury and Venus they don't have them at all, Mars- two, y Of the earth- one).
The similarity of the terrestrial planets does not exclude some differences. For example, Venus, unlike other planets, rotates in the direction opposite to its movement around the Sun, and is 243 times slower than the Earth.
Period of circulation Mercury(i.e., the year of this planet) is only 1/3 longer than the period of its rotation around the axis.
The angles of inclination of the axes to the planes of their orbits y Of the earth and at Mars approximately the same, but completely different for Mercury and Venus... Same as Earth, there are seasons on Mars, although almost twice as long as The earth.
Similarities and differences are also found in the atmospheres of planets. terrestrial group... Unlike Mercury which, like Moon, practically devoid of atmosphere, Venus and Mars possess it.
Venus has a very dense atmosphere, mainly composed of carbon dioxide and sulfur compounds. Atmosphere Mars on the contrary, it is extremely rarefied and also poor in oxygen and nitrogen. Surface pressure Venus almost 100 times more, while Mars almost 150 times less than the surface Of the earth.
Outer planets include Neptune, Uranus, Saturn, Jupiter, Pluto.
GIANT PLANETS Jupiter, Saturn, Uranus and Neptune does not at all correspond to our ideas about comfort: it is very cold, terrible gas composition (methane, ammonia, hydrogen, etc.), there is practically no solid surface - only a dense atmosphere and an ocean of liquid gases. All of this is very unlike Earth. However, in the era of the origin of life, the Earth was not at all the same as it is now. Its atmosphere was more like Venusian and Jupiterian, except that it was warmer. Therefore, in the near future, the search for organic compounds in the atmosphere of the giant planets will certainly be carried out.
The giant planets are far from the Sun, and regardless of the nature of the change of seasons, they are always dominated by low dark temperatures. On Jupiter there is no change of seasons at all, since the axis of this planet is almost perpendicular to the plane of its orbit. The seasons change in a peculiar way on the planet. Uranus, since the axis of this planet is inclined to the orbital plane at an angle of 8¦.
The giant planets are distinguished by a large number of satellites; Jupiter has found 16 of them to date, Saturn - 17, Uranus- 16 and y Neptune- 8. An interesting feature of the giant planets is the rings that were found not only in Saturn but also at Jupiter, Uranus and Neptune.
The most important feature of the structure of giant planets is that these planets have a solid surface. They are composed mainly of light elements - hydrogen and helium.
Orbits the planets are elliptical with the Sun at one focus, although all of them, except for the orbits of Mercury and Pluto, are almost circular. All the orbits of the planets are more or less in the same plane (called ecliptic and determined from the plane of the Earth's orbit)... The plane of the ecliptic is tilted only 7 degrees from the plane of the equator of the Sun. Pluto's orbit deviates most from the plane of the ecliptic (by 17 degrees). The diagram above shows the relative sizes of the orbits of the nine planets as viewed from above the ecliptic (hence not circular). They all rotate in the same direction (clockwise when viewed downward from the sun's north pole; all but Venus, Uranus and Pluto rotate in the same direction.
The image above shows nine planets with approximately correct relative dimensions(see other similar images and comparison of terrestrial planets or Appendix 2 for more details).
One way to imagine real size The solar system is to imagine a model in which all sizes and distances are reduced by a billion times (1e9). Then the Earth will be about 1.3 cm in diameter (about the size of a grape). The moon rotates at a distance of ~ 30 cm from it. The sun in this case will be 1.5 meters in diameter (approximately the height of a person) and is located at a distance of 150 meters (approximately a city block) from the Earth. Jupiter is 15 cm in diameter (the size of a large grapefruit) and is 5 city blocks from the Sun. Saturn - (about the size of an orange) 10 blocks away; Uranus and Neptune (lemons) - 20 and 30 blocks. A person on this scale will be the size of an atom; and the nearest star is at a distance of 40,000 km.
Not shown in the upper illustration are numerous small bodies that are in the solar system: satellites of the planets; big number asteroids (small stone bodies) orbiting the sun, mainly between Mars and Jupiter, but also elsewhere; and comets (small ice bodies) that come and go from the inner solar system in highly elevated orbits and random orientations to the ecliptic. With a few exceptions, satellites of planets rotate in the same way as their planets and are approximately in the plane of the ecliptic, but this is not always the case for comets and asteroids.
Classification
The classification of these bodies is the subject of much controversy.... Traditionally, the solar system has been subdivided into planets(large bodies revolving around the Sun), their satellites(or moons, objects of various sizes orbiting planets), asteroids(low-density objects orbiting the sun) and comets(small ice bodies with highly eccentric orbits). Unfortunately, the solar system turned out to be more complex than it was thought:- there are several satellites larger than Pluto and two larger than Mercury;
- there are several small satellites that are likely captured asteroids;
- comets sometimes fizzle out and become indistinguishable from asteroids;
- objects from the Kuiper Belt and others like Chiron do not fit this pattern so well;
- The Earth / Moon and Pluto / Charon systems are sometimes referred to as "binary planets".
The nine bodies traditionally referred to as planets are often further classified as follows:
- by composition:
- earthly or rocky planets: Mercury, Venus, Earth, and Mars:
- The terrestrial planets are composed mainly of stone and metal and have relatively high densities, do not rotate much, have a hard surface, do not have rings, and the number of satellites is small.
- giant planetsor gas planets: Jupiter, Saturn, Uranus, and Neptune:
- Gas planets are composed primarily of hydrogen and helium and are usually low densities, spinning rapidly, deep atmospheres, rings, and a large number of satellites.
- Pluto.
- earthly or rocky planets: Mercury, Venus, Earth, and Mars:
- to size:
- small planets: Mercury, Venus, Earth, Mars and Pluto.
- The diameter of the small planets is less than 13,000 km.
- giant planets: Jupiter, Saturn, Uranus, Neptune.
- The diameter of these planets is more than 48,000 km.
- Mercury and Pluto are sometimes represented as the smallest planets (do not confuse with minor planets, this is the official term for asteroids).
- Giant planets are sometimes also classified as gas giants.
- small planets: Mercury, Venus, Earth, Mars and Pluto.
- by location relative to the Sun:
- internal planets of the solar system: Mercury, Venus, Earth and Mars.
- external planets of the solar system: Jupiter, Saturn, Uranus, Neptune and Pluto.
- The asteroid belt between Mars and Jupiter is the border between the inner and outer solar systems.
- by location relative Of the earth :
- internal planets: Mercury and Venus.
- closer to the sun than the earth.
- These planets, when viewed from Earth, show phases similar to those of the moon.
- Earth.
- external planets: from Mars to Pluto.
- farther from the Sun than the Earth.
- These planets always seem to be full or so.
- internal planets: Mercury and Venus.
- on history:
- classic planets: Mercury, Venus, Mars, Jupiter, Saturn.
- known since prehistoric times
- observed with the naked eye
- modern planets: Uranus, Neptune, Pluto.
- are currently open
- visible only through a telescope
- Earth.
- classic planets: Mercury, Venus, Mars, Jupiter, Saturn.
Pictures
Comment: most images in Nine Planets do not accurately convey the color of the object. Most of them were created by combining several black and white images obtained through various color filters. Although the colors look "believable" enough, they are not quite what you see them.- Montage of Nine Planets (large version on top) 36k jpg
- Other Comparative characteristics sizes (from LANL) 93k gif
- Sun and large planets, comparison (from Extrema) 41k gif
- Earth and small bodies, comparison (from Extrema) 35k gif
- Voyager 1 mosaic of the solar system from a distance of 4 billion miles 36k jpg; 85k gif (caption)
- Voyager 1 image of 6 planets from a distance of 4 billion miles 123k jpg; 483k gif
- Pale Blue Dot, mirrored above by Carl Sagan.
A more general overview
- The history of the discovery of the solar system
- Solar system. Introduction from LANL
- Family Portrait of the Solar System from NSSDC
- The life of the solar system, interactive information from the web.
- Our Solar System from NASA Spacelink
- notes on highly distant objects in the solar system (from RGO)
- planetary surface temperature notes (from RGO)
- scaled models of the solar system
- Scaled Model of the Solar System Meta Page (links to others)
- Lakeview Museum Community Solar System, the world's largest scaled model of the solar system from LPI
- Sagan Planet Walk in Ithaca, NY
- Building the solar system, calculating scaled models
- Silver City, NM
- Solar System Walk in Gainesville, Florida
- PlanetTrek, a scaled model of the solar system
- Walking through the solar system, visual size calculations for comparison from Exploratorium
The planets of the solar system
According to the official position of the International Astronomical Union (IAS), the organization that assigns names to astronomical objects, there are only 8 planets.
Pluto was excluded from the category of planets in 2006. since in the Kuiper belt there are objects that are larger / or equal in size to Pluto. Therefore, even if it is taken for a full-fledged celestial body, then it is necessary to add Eris to this category, which has almost the same size with Pluto.
As defined by MAC, there are 8 known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
All planets are divided into two categories depending on their physical characteristics: the terrestrial group and the gas giants.
Schematic representation of the location of the planets
Terrestrial planets
Mercury
The smallest planet in the solar system has a radius of only 2,440 km. The period of revolution around the Sun, for ease of understanding, equated to the Earth's year, is 88 days, while Mercury manages to complete a revolution around its own axis only one and a half times. Thus, its day lasts approximately 59 Earth days. For a long time it was believed that this planet was all the time turned to the Sun by the same side, since the periods of its visibility from the Earth were repeated with a frequency approximately equal to four Mercury days. This misconception was dispelled with the advent of the possibility of using radar research and conducting constant observations using space stations. The orbit of Mercury is one of the most unstable, changing not only the speed of movement and its distance from the Sun, but also the position itself. Anyone interested can observe this effect.
Mercury in color, image from the MESSENGER spacecraft
The proximity to the Sun has caused Mercury to experience the largest temperature fluctuations among the planets of our system. The average daytime temperature is around 350 degrees Celsius and the nighttime temperature is -170 ° C. Sodium, oxygen, helium, potassium, hydrogen and argon were found in the atmosphere. There is a theory that he was previously a satellite of Venus, but so far this remains unproven. He has no satellites of his own.
Venus
The second planet from the Sun, the atmosphere of which is almost entirely composed of carbon dioxide. It is often called the Morning Star and the Evening Star, because it is the first of the stars that becomes visible after sunset, just as before dawn it continues to be visible even when all other stars have disappeared from sight. The percentage of carbon dioxide in the atmosphere is 96%, nitrogen in it is relatively small - almost 4%, and water vapor and oxygen are present in very small quantities.
Venus in the UV spectrum
This atmosphere creates a greenhouse effect, the surface temperature is therefore even higher than that of Mercury and reaches 475 ° C. It is considered the most leisurely, the Venusian day lasts 243 Earth days, which is almost equal to a year on Venus - 225 Earth days. Many call it the sister of the Earth because of its mass and radius, the values of which are very close to those of the Earth. The radius of Venus is 6052 km (0.85% of the Earth). There are no satellites, like Mercury.
The third planet from the Sun and the only one in our system where there is liquid water on the surface, without which life on the planet could not develop. At least life as we know it. The radius of the Earth is 6371 km and, unlike the rest of the celestial bodies of our system, more than 70% of its surface is covered with water. The rest of the space is occupied by continents. Another feature of the Earth is the tectonic plates hidden under the planet's mantle. At the same time, they are able to move, albeit at a very low speed, which over time causes a change in the landscape. The speed of the planet moving along it is 29-30 km / sec.
Our planet from space
One revolution around its axis takes almost 24 hours, and full walkthrough in orbit lasts 365 days, which is much longer in comparison with the nearest neighboring planets. The Earth's day and year are also taken as a standard, but this was done only for the convenience of perception of time intervals on the other planets. The Earth has one natural satellite - the Moon.
Mars
The fourth planet from the Sun, known for its tenuous atmosphere. Since 1960, Mars has been actively explored by scientists from several countries, including the USSR and the United States. Not all exploration programs have been successful, but water found in some areas suggests that primitive life on Mars exists, or has existed in the past.
The brightness of this planet allows you to see it from Earth without any instruments. Moreover, once every 15-17 years, during the Opposition, it becomes the brightest object in the sky, eclipsing even Jupiter and Venus.
The radius is almost half that of the Earth and is 3390 km, but the year is much longer - 687 days. He has 2 satellites - Phobos and Deimos .
An illustrative model of the solar system
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The sun
The sun is a star, which is a hot ball of incandescent gases at the center of our solar system. Its influence extends far beyond the orbits of Neptune and Pluto. Without the Sun and its intense energy and heat, there would be no life on Earth. There are billions of stars, like our Sun, scattered across the Milky Way galaxy.
Mercury
Scorched by the Sun, Mercury is only slightly larger than Earth's satellite Moon. Like the Moon, Mercury is practically devoid of an atmosphere and cannot smooth out the traces of impact from falling meteorites, therefore, like the Moon, it is covered with craters. The daytime side of Mercury gets very hot on the Sun, while on the night side the temperature drops hundreds of degrees below zero. There is ice in the craters of Mercury, which are located at the poles. Mercury makes one revolution around the Sun every 88 days.
Venus
Venus is a world of monstrous heat (even more than on Mercury) and volcanic activity. Similar in structure and size to Earth, Venus is covered in a thick and toxic atmosphere that creates a strong greenhouse effect. This scorched world is hot enough to melt lead. Radar images through the mighty atmosphere have revealed volcanoes and warped mountains. Venus rotates in the opposite direction from the rotation of most planets.
Earth is an ocean planet. Our home, with its abundance of water and life, makes it unique in our solar system. Other planets, including several moons, also have ice deposits, atmosphere, seasons and even weather, but only on Earth did all these components come together in such a way that life became possible.
Mars
Although details of Mars' surface are difficult to see from Earth, telescope observations show that Mars has seasons and white spots at the poles. For decades, people believed that the bright and dark areas on Mars were patches of vegetation and that Mars might be a suitable place to live, and that water exists in the polar caps. When the spacecraft Mariner 4 flew off Mars in 1965, many of the scientists were shocked to see photographs of the gloomy planet covered in craters. Mars turned out to be a dead planet. Later missions, however, revealed that Mars holds many secrets that still remain to be solved.
Jupiter
Jupiter is the most massive planet in our solar system, with four large moons and many small moons. Jupiter forms a kind of miniature solar system. To turn into a full-fledged star, Jupiter had to become 80 times more massive.
Saturn
Saturn is the farthest of the five planets that were known before the invention of the telescope. Like Jupiter, Saturn is composed primarily of hydrogen and helium. Its volume is 755 times that of the Earth. Winds in its atmosphere reach speeds of 500 meters per second. These fast winds, combined with the heat rising from the planet's interior, are causing the yellow and golden streaks we see in the atmosphere.
Uranus
The first planet found with a telescope, Uranus was discovered in 1781 by astronomer William Herschel. The seventh planet is so far from the Sun that one revolution around the Sun takes 84 years.
Neptune
Nearly 4.5 billion kilometers from the Sun, distant Neptune orbits. It takes 165 years for one revolution around the Sun. It is invisible to the naked eye due to its great distance from Earth. It is interesting that its unusual elliptical orbit intersects with the orbit of the dwarf planet Pluto, which is why Pluto is inside the orbit of Neptune for about 20 years out of 248 during which it makes one revolution around the Sun.
Pluto
Tiny, cold and incredibly distant, Pluto was discovered in 1930 and has long been considered the ninth planet. But after the discoveries of Pluto-like worlds that were even further away, Pluto was transferred to the category of dwarf planets in 2006.
Planets are giants
There are four gas giants located beyond the orbit of Mars: Jupiter, Saturn, Uranus, Neptune. They are found in the outer solar system. They are distinguished by their massiveness and gas composition.
Planets of the solar system, not to scale
Jupiter
The fifth in a row from the Sun and the largest planet in our system. Its radius is 69912 km, it is 19 times larger than the Earth and only 10 times smaller than the Sun. The year on Jupiter is not the longest in the solar system, it lasts 4333 Earth days (less than 12 years). His own day has a duration of about 10 Earth hours. The exact composition of the planet's surface has not yet been determined, but it is known that krypton, argon and xenon are present on Jupiter in much larger quantities than on the Sun.
It is believed that one of the four gas giants is actually a failed star. This theory is supported by the largest number of satellites, of which Jupiter has many - as many as 67. To imagine their behavior in the planet's orbit, a sufficiently accurate and precise model of the solar system is needed. The largest of them are Callisto, Ganymede, Io and Europa. At the same time, Ganymede is the largest satellite of the planets in the entire solar system, its radius is 2634 km, which is 8% larger than the size of Mercury, the smallest planet in our system. Io differs in that it is one of three satellites with an atmosphere.
Saturn
The second largest planet and the sixth in the solar system. Compared to other planets, the composition is most similar to the Sun chemical elements... The radius of the surface is 57350 km, the year is 10 759 days (almost 30 Earth years). The day here lasts a little longer than on Jupiter - 10.5 Earth hours. By the number of satellites, it is not much behind its neighbor - 62 against 67. The largest satellite of Saturn is Titan, just like Io, which has an atmosphere. Slightly smaller in size, but no less famous from this - Enceladus, Rhea, Dione, Tethys, Iapetus and Mimas. It is these satellites that are the objects for the most frequent observation, and therefore we can say that they are the most studied in comparison with the rest.
For a long time, the rings on Saturn were considered a unique phenomenon inherent only to him. It has only recently been established that rings are present in all gas giants, but in others they are not so clearly visible. Their origin has not yet been established, although there are several hypotheses about how they came about. In addition, quite recently it was discovered that Rhea, one of the satellites of the sixth planet, also possesses a kind of rings.
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