The solar system includes the central star and all the natural space objects orbiting it. It was formed by gravitational compression of a gas and dust cloud approximately 4.57 billion years ago. The Solar System includes 8* planets, half of which belong to the terrestrial group: Mercury, Venus, Earth and Mars. They are also called the inner planets in contrast to the outer planets - the giant planets Jupiter, Saturn, Uranus and Neptune, located outside the ring of minor planets.
1. Mercury
The planet closest to the Sun in the Solar System is named after the ancient Roman god of commerce, the fleet-footed Mercury, because it moves across the celestial sphere faster than other planets.
2. Venus
The second planet of the solar system was named in honor of the ancient Roman goddess of love Venus. It is the brightest object in the earth's sky after the Sun and Moon and the only planet in the solar system named after a female deity.
3. Earth
The third planet from the Sun and the fifth largest among all the planets in the Solar System has had its current name since 1400, but who exactly named it that is unknown. The English word Earth comes from an 8th century Anglo-Saxon word meaning earth or ground. This is the only planet in the solar system with a name that is not related to Roman mythology.
4. Mars
The seventh largest planet in the solar system has a reddish tint to its surface due to iron oxide. With such a “bloody” association, the object was named after the ancient Roman god of war, Mars.
5. Jupiter
The largest planet in the solar system is named after the ancient Roman supreme god of thunder. 6. Saturn Saturn is the slowest planet in the solar system, which is symbolically reflected in its first name: it was given in honor of the ancient Greek god of time, Kronos. In Roman mythology, the god of agriculture Saturn turned out to be the analogue of Kronos, and as a result, this name was assigned to the planet.
7. Uranus
The third largest planet in diameter and fourth largest planet in the solar system was discovered in 1781 by the English astronomer William Herschel. The tradition of naming planets was continued, and the international community named the new celestial body in honor of the father of Kronos, the Greek god of the sky, Uranus.
8. Neptune
Discovered on September 23, 1846, Neptune became the first planet discovered through mathematical calculations rather than through regular observations. The large blue giant (this color is due to the hue of the atmosphere) is named after the Roman god of the seas.
Pluto In 2006, it lost its status as a solar system planet and was classified as a dwarf planet and the largest object in the Kuiper belt. It has been the ninth planet of the solar system since its discovery in 1930. The name "Pluto" was first suggested by an eleven-year-old schoolgirl from Oxford, Venetia Bernie. She was interested not only in astronomy, but also in classical mythology, and decided that this name - an ancient Roman version of the name of the Greek god of the underworld - was best suited for a dark, distant and cold world. By voting, astronomers chose this option.
Look at the model of the solar system created in the American desert.
*Recently scientists. Since it does not yet have a full name, and research is still ongoing, we did not include it in the above list.
Our home in space is the Solar System, a star system consisting of eight planets and part of the Milky Way galaxy. In the center is a star called the Sun. The solar system is four and a half billion years old. We live on the third planet from the sun. Do you know about other planets in the solar system?! Now we will tell you a little about them.
Mercury- the smallest planet in the solar system. Its radius is 2440 km. The period of revolution around the Sun is 88 Earth days. During this time, Mercury manages to rotate around its own axis only one and a half times. A day on Mercury lasts approximately 59 Earth days. The orbit of Mercury is one of the most unstable: not only the speed of movement and its distance from the Sun, but also the position itself changes there. There are no satellites.
Neptune- the eighth planet of the solar system. It is located quite close to Uranus. The radius of the planet is 24547 km. A year on Neptune is 60,190 days, that is, about 164 Earth years. Has 14 satellites. It has an atmosphere in which the strongest winds have been recorded - up to 260 m/s.
By the way, Neptune was discovered not through observations, but through mathematical calculations.
Uranus- the seventh planet in the solar system. Radius - 25267 km. The coldest planet has a surface temperature of -224 degrees. A year on Uranus is equal to 30,685 Earth days, that is, approximately 84 years. Day - 17 hours. Has 27 satellites.
Saturn- the sixth planet of the solar system. The radius of the planet is 57350 km. It is second in size after Jupiter. A year on Saturn is 10,759 days, which is almost 30 Earth years. A day on Saturn is almost equal to a day on Jupiter - 10.5 Earth hours. It is most similar to the Sun in the composition of chemical elements.
Has 62 satellites.
The main feature of Saturn is its rings. Their origin has not yet been established.
Jupiter- the fifth planet from the Sun. It is the largest planet in the solar system. The radius of Jupiter is 69912 km. This is as much as 19 times larger than the Earth. A year there lasts as many as 4333 Earth days, that is, almost less than 12 years. A day is about 10 Earth hours long.
Jupiter has as many as 67 satellites. The largest of them are Callisto, Ganymede, Io and Europa. Moreover, Ganymede is 8% larger than Mercury, the smallest planet in our system, and has an atmosphere.
Mars- the fourth planet of the solar system. Its radius is 3390 km, which is almost half the size of the Earth. A year on Mars is 687 Earth days. It has 2 satellites - Phobos and Deimos.
The planet's atmosphere is thin. Water found on some areas of the surface suggests that some kind of primitive life on Mars was once before or even exists now.
Venus- the second planet of the solar system. It is similar in mass and radius to the Earth. There are no satellites.
The atmosphere of Venus consists almost entirely of carbon dioxide. The percentage of carbon dioxide in the atmosphere is 96%, nitrogen - approximately 4%. Water vapor and oxygen are also present, but in very small quantities. Due to the fact that such an atmosphere creates a greenhouse effect, the temperature on the surface of the planet reaches 475 °C. A day on Venus is equal to 243 Earth days. A year on Venus is 255 days.
Pluto is a dwarf planet on the edges of the solar system, which is the dominant object in a distant system of 6 small cosmic bodies. The radius of the planet is 1195 km. Pluto's orbital period around the Sun is approximately 248 Earth years. A day on Pluto is 152 hours long. The mass of the planet is approximately 0.0025 the mass of the Earth.
It is noteworthy that Pluto was excluded from the category of planets in 2006 due to the fact that in the Kuiper belt there are objects that are larger or equal in size to Pluto, which is why, even if it is accepted as a full-fledged planet, then in this case it is necessary Add Eris to this category - which is almost the same size as Pluto.
This is a system of planets, in the center of which there is a bright star, a source of energy, heat and light - the Sun.
According to one theory, the Sun was formed along with the Solar System about 4.5 billion years ago as a result of the explosion of one or more supernovae. Initially, the Solar System was a cloud of gas and dust particles, which, in motion and under the influence of their mass, formed a disk in which a new star, the Sun, and our entire Solar System arose.
At the center of the solar system is the Sun, around which nine large planets revolve in orbit. Since the Sun is displaced from the center of planetary orbits, during the cycle of revolution around the Sun the planets either approach or move away in their orbits.
There are two groups of planets:
Terrestrial planets: And . These planets are small in size with a rocky surface and are closest to the Sun.
Giant planets: And . These are large planets, consisting mainly of gas and characterized by the presence of rings consisting of icy dust and many rocky chunks.
And here does not fall into any group, because, despite its location in the solar system, it is located too far from the Sun and has a very small diameter, only 2320 km, which is half the diameter of Mercury.
Planets of the Solar System
Let's begin a fascinating acquaintance with the planets of the Solar System in order of their location from the Sun, and also consider their main satellites and some other space objects (comets, asteroids, meteorites) in the gigantic expanses of our planetary system.
Rings and moons of Jupiter: Europa, Io, Ganymede, Callisto and others...
The planet Jupiter is surrounded by a whole family of 16 satellites, and each of them has its own unique features...
Rings and moons of Saturn: Titan, Enceladus and others...
Not only the planet Saturn has characteristic rings, but also other giant planets. Around Saturn, the rings are especially clearly visible, because they consist of billions of small particles that revolve around the planet, in addition to several rings, Saturn has 18 satellites, one of which is Titan, its diameter is 5000 km, which makes it the largest satellite in the solar system...
Rings and moons of Uranus: Titania, Oberon and others...
The planet Uranus has 17 satellites and, like other giant planets, there are thin rings surrounding the planet that have practically no ability to reflect light, so they were discovered not so long ago in 1977, completely by accident...
Rings and moons of Neptune: 
Triton, Nereid and others...
Initially, before the exploration of Neptune by the Voyager 2 spacecraft, two satellites of the planet were known - Triton and Nerida. An interesting fact is that the Triton satellite has a reverse direction of orbital motion; strange volcanoes were also discovered on the satellite that erupted nitrogen gas like geysers, spreading a dark-colored mass (from liquid to vapor) many kilometers into the atmosphere. During its mission, Voyager 2 discovered six more moons of the planet Neptune...
Previously, a planet was any cosmic body that orbits a star, emits light that is reflected by that star, and is larger than an asteroid. Even in Ancient Greece, they talked about 7 planets as luminous bodies that move across the sky against the backdrop of stars. These are Mercury, Sun, Venus, Mars, Moon, Jupiter, Saturn. Please note that the Sun is indicated here, which is a star, and the Moon is a satellite of our Earth. The earth is not included in this list because the Greeks considered it the center of everything.
In the 15th century, Copernicus discovered that the center of the system was the Sun, not the Earth. He laid out his statements in his work “On the Revolution of the Celestial Spheres.” The Moon and Sun were removed from the list, and planet Earth was included. When telescopes were invented, three more planets were discovered. Uranus in 1781, Neptune in 1846, Pluto in 1930, which, by the way, is no longer considered a planet.
At the moment, researchers are giving a new meaning to the word “planet”, namely: it is a celestial body that satisfies 4 conditions:
- The body must rotate around the star.
- Have a spherical or approximately spherical shape, that is, the body must have sufficient gravity.
- It doesn't have to be a star.
- The celestial body should not have other large bodies near its orbit.
A star is a body that emits light and has a powerful source of energy.
Planets in the Solar System
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The solar system includes the planets and other objects that orbit the sun. 4.5 billion years ago, condensations of clouds of stellar matter began to form in the Galaxy. The gases heated up and radiated heat. As a result of an increase in temperature and density, nuclear reactions began, hydrogen turned into helium. This is how the most powerful source of energy arose - the Sun. This process took tens of millions of years. Planets with satellites were created. The formation of the solar system ended completely about 4 billion years ago.
Today, the solar system includes 8 planets, which are divided into two groups. The first is the terrestrial group, the second is the gas giants. The terrestrial planets - Venus, Mercury, Mars and Earth - are composed of silicates and metals. The gas giants - Saturn, Jupiter, Neptune and Uranus - are composed of hydrogen and helium. The planets have different sizes, both in comparison between the two groups and among themselves. Accordingly, the giants are much larger and more massive than the terrestrial planets.
Mercury is closest to the Sun, followed by Neptune. Before characterizing the planets of the Solar System, we need to talk about its main object - the Sun. This is the star through which all living and nonliving things in the system began to exist. The sun is a spherical, plasma, hot ball. A large number of space objects revolve around it - satellites, planets, meteorites, asteroids and cosmic dust. This star appeared about 5 billion years ago. Its mass is 300 thousand times greater than the mass of our planet. The core temperature is 13 million degrees Kelvin, and at the surface - 5 thousand degrees Kelvin (4727 degrees Celsius). In the Milky Way galaxy, the Sun is one of the largest and brightest stars. The distance from the Sun to the center of the Galaxy is 26,000 light years. The Sun makes a complete revolution around the galactic center every 230-250 million years.
Mercury
It is closest to the Sun and is the smallest planet in the solar system. The planet has no satellites. There are many craters on the surface of Mercury, which were formed by many meteorites that fell on the planet more than 3 billion years ago. Their diameter is varied - from a couple of meters to 1000 kilometers. The planet's atmosphere is composed mainly of helium and is blown by wind from the Sun. Temperatures can reach +440 degrees Celsius. The planet completes a revolution around the Sun in 88 Earth days. A day on the planet is equal to 176 Earth hours.
Venus
Venus is the second planet from the Sun. Its dimensions are close to the size of the Earth. The planet has no satellites. The atmosphere consists of carbon dioxide with admixtures of nitrogen and oxygen. The air pressure is 90 atmospheres, which is 35 times more than on Earth. Venus is called the hottest planet because its dense atmosphere, carbon dioxide, proximity to the Sun and the greenhouse effect create very high temperatures on the planet's surface. It can reach 460 degrees Celsius. Venus can be seen from the surface of the Earth. This is the brightest cosmic object after the Moon and the Sun.
Earth
The only planet suitable for life. Maybe it exists on other planets, but no one can say this with certainty yet. It is the largest in its group in terms of mass, density and size. Its age is more than 4 billion years. Life began here more than 3 billion years ago. Earth's satellite is the Moon. The atmosphere on the planet is radically different from others. Most of it consists of nitrogen. This also includes carbon dioxide, oxygen, water vapor and argon. The ozone layer and magnetic field make the level of solar and cosmic radiation less. Due to the content of carbon dioxide in the Earth's atmosphere, a greenhouse effect is formed on the planet. Without it, the temperature on the Earth's surface would be 40 degrees lower. Islands and continents occupy 29% of the planet's surface, and the rest is the World Ocean.
Mars
It is also called the “red planet” due to the presence of large amounts of iron oxide in the soil. Mars is the seventh largest planet in the solar system. Two satellites fly near the planet - Deimos and Phobos. Due to the too thin atmosphere and the far distance from the Sun, the average annual temperature of the planet is minus 60 degrees. At some points during the day, temperature changes can reach 40 degrees. The presence of volcanoes and craters, deserts and valleys, and polar ice caps distinguishes Mars from other planets in the solar system. Also here is the highest mountain - the extinct Olympus volcano, which reached a height of 27 kilometers. Valles Marineris is the largest canyon among the planets. Its length is 4500 km and its depth is 11 m.
Jupiter
It is the largest planet in the solar system. Jupiter is 318 times heavier than Earth and 2.5 times more massive compared to other planets. The main components of the planet are helium and hydrogen. Jupiter emits a lot of heat - 4 * 1017 W. To become a star like the Sun, it must reach 70 times its current mass. The planet has the largest number of satellites - 63. Europa, Callisto, Ganymede and Io are the largest of them. Ganymede is also the largest moon in the entire solar system and is even larger than Mercury. Jupiter's atmosphere hosts many vortices that have a brownish-red colored band of clouds, or a giant storm, known as the Great Red Spot since the 17th century.
Saturn
Like Jupiter, it is a large planet that follows Jupiter in size. The ring system, which consists of particles of ice of various sizes, rocks and dust, distinguishes this planet from others. It has one fewer satellites than Jupiter. The largest are Enceladus and Titan. In composition, Saturn resembles Jupiter, but in density it is inferior to the simplest water. The atmosphere looks quite homogeneous and calm, which can be explained by a dense layer of fog. Saturn has enormous wind speeds, it can reach 1800 km per hour.
Uranus
This planet was discovered first using a telescope. Uranus is the only planet in the solar system that lies on its side and orbits the sun. Uranus has 27 moons, which are named after characters in Shakespeare's plays. The largest among them are Titania, Oberon and Umbriel. Uranus contains a large number of high-temperature modifications of ice. It is also the coldest planet. The temperature here is minus 224 degrees Celsius.
Neptune
It is the farthest planet from the Sun, although until 2006 this title belonged to Pluto. This planet was discovered without the help of a telescope, but by mathematical calculations. The existence of Neptune was suggested to scientists by Uranus, on which strange changes were discovered while moving in its own orbit. The planet has 13 satellites. The largest among them is Triton. Its peculiarity is that it moves opposite to the planet. The strongest winds in the solar system blow in the same direction, the speed of which reaches 2200 km per hour. Neptune and Uranus have similar compositions, but it is also similar in composition to Jupiter and Saturn. The planet has an internal heat source, from which it receives 2.5 times more energy than from the Sun. There is methane in the outer layers of the atmosphere, which gives the planet a blue tint.
That's how mysterious the world of Space is. Many satellites and planets have their own characteristics. Scientists are making changes to this world, for example, they excluded Pluto from the list of planets.
Study the planets on the portal website - it’s very interesting.
Rotation of planets
All planets, in addition to their orbit, also rotate around their own axis. The period during which they make a full revolution is defined as an epoch. Most of the planets in the Solar System rotate in the same direction on the axis as the Sun, but Uranus and Venus rotate in the opposite direction. Scientists observe a big difference in the length of the day on the planets - Venus takes 243 Earth days to complete one revolution around its axis, while the gas giant planets need only a couple of hours. The rotation period of exoplanets is unknown, but their close proximity to the stars means that eternal day reigns on one side, and eternal night on the other.
Why are all the planets so different? Due to the high temperature closer to the star, the ice and gas evaporated very quickly. The giant planets failed to form, but an accumulation of metal particles occurred. Thus, Mercury was formed, which contains the largest amount of metals. The further we are from the center, the lower the temperature. Celestial bodies appeared, where a significant percentage was made up of rocks. The four planets that are located closer to the center of the solar system are called the inner ones. With the discovery of new systems, more and more questions arise. New research will help answer them.
Scientists claim that our system is unique. All planets are built in strict order. The largest one is closer to the Sun, respectively, the smallest one is further away. Our system has a more complex structure, because the planets are not arranged according to their mass. The sun makes up more than 99 percent of all objects in the system.