Which planet of the solar system is 7. Sizes of the planets of the solar system in ascending order and interesting information about the planets. Prospects for discovering Planet X

People need not only spectacles and solutions to pressing problems. It is interesting, for example, to know: how many planets are there in the solar system? Of course, the answer to this question is unlikely to be of practical importance, but a broad outlook will not hurt in any case. The desire to understand the surrounding reality, how everything works, and increasing one’s own authority among colleagues and friends encourages one to learn new information and strive to understand a wide variety of topics. So, let's count how many planets are in our solar system.

Mercury

This is the celestial body closest to the Sun and the smallest in its system. Interestingly, Mercury has a core made of iron and a very thin surface crust.

Venus

It is the second planet from the Sun. It is almost the same size as the Earth, but the temperature on Venus is about four hundred degrees Celsius! If we were looking for an answer to the question not about how many planets there are in the solar system, but about the number of celestial bodies in it that are suitable for existence, then Venus, with its concentration of greenhouse gases, would leave no chance for life in any known us form.

Earth

Only here, on planet Earth, there is a hydrosphere - the source of all life! Imagine - there is no other planet in the solar system with such a treasure!

Mars

The soil of this planet contains a huge amount of iron oxide. Hence the red color of Mars. This fourth celestial object from the Sun is the last of the so-called inner group of planets. By the way, along the way we found out how many planets in the solar system are in this group: there are four of them. But we will go further.

Jupiter

It is a giant outer group celestial body with an impressive escort of 65 satellites. Ganymede is one of them, the largest: its dimensions exceed Mercury! Hydrogen and helium are the main components of Jupiter.

Saturn

Another giant gas planet. Saturn is easily recognized by its beautiful belt of asteroid rings revolving around the celestial body. The density of Saturn is similar to the density of Earth's water, and this planet has slightly fewer satellites than Jupiter - 62. The most interesting of them is Titan, which has an atmosphere.

Uranus

From the outer row solar system Uranus is the lightest celestial object. It is interesting that the angle of rotation of the axis of this planet is different from all the others. Uranus is like a huge, cold bowling ball rolling in orbit. By the way, of all the planets, it emits the least heat.

Neptune

The most distant planet of the solar system is Neptune. It is interesting because the rotation of its satellite Triton is directed in reverse side from the planet.

How many planets are there in the solar system

Answering this question, it is easy to calculate: four planets of the inner group and the same number of outer ones add up to eight. If you are wondering why Pluto is not on this list, know that thanks to scientists, since 2006 this celestial object has “lost” its status as a planet.

On March 13, 1781, English astronomer William Herschel discovered the seventh planet of the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet of the solar system - Pluto. By the beginning of the 21st century, it was believed that the solar system included nine planets. However, in 2006, the International Astronomical Union decided to strip Pluto of this status.

There are already 60 known natural satellites of Saturn, most of which were discovered using spacecraft. Most of the satellites consist of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christiaan Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only moon to have a very dense atmosphere, 1.5 times larger than Earth's, consisting primarily of 90% nitrogen, with moderate methane content.

The International Astronomical Union officially recognized Pluto as a planet in May 1930. At that moment, it was assumed that its mass was comparable to the mass of the Earth, but later it was found that Pluto’s mass is almost 500 times less than the Earth’s, even less than the mass of the Moon. Pluto's mass is 1.2 x 10.22 kg (0.22 Earth's mass). Pluto's average distance from the Sun is 39.44 AU. (5.9 to 10 to 12 degrees km), radius is about 1.65 thousand km. The period of revolution around the Sun is 248.6 years, the period of rotation around its axis is 6.4 days. Pluto's composition is believed to include rock and ice; the planet has a thin atmosphere consisting of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nix.

At the end of XX and beginning of XXI centuries, many objects have been discovered in the outer solar system. It has become obvious that Pluto is only one of the largest Kuiper Belt objects known to date. Moreover, at least one of the belt objects - Eris - is a larger body than Pluto and is 27% heavier. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a “planet”, but a “dwarf planet”.

At the conference, a new definition of a planet was developed, according to which planets are considered bodies that revolve around a star (and are not themselves a star), have a hydrostatically equilibrium shape and have “cleared” the area in the area of ​​their orbit from other, smaller objects. Dwarf planets will be considered objects that orbit a star, have a hydrostatically equilibrium shape, but have not “cleared” the nearby space and are not satellites. Planets and dwarf planets are two different classes of objects in the Solar System. All other objects orbiting the Sun that are not satellites will be called small bodies of the Solar System.

Thus, since 2006, there have been eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The International Astronomical Union officially recognizes five dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.

On June 11, 2008, the IAU announced the introduction of the concept of "plutoid". It was decided to call celestial bodies revolving around the Sun in an orbit whose radius is greater than the radius of Neptune’s orbit, whose mass is sufficient for gravitational forces to give them an almost spherical shape, and which do not clear the space around their orbit (that is, many small objects revolve around them) ).

Since it is still difficult to determine the shape and thus the relationship to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily classifying all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1 as plutoids. If it later turns out that an object classified as a plutoid is not a dwarf planet, it will be deprived of this status, although the assigned name will be retained. The dwarf planets Pluto and Eris were classified as plutoids. In July 2008, Makemake was included in this category. On September 17, 2008, Haumea was added to the list.

The material was prepared based on information from open sources

> Planets

Explore everything planets of the solar system in order and study the names, new scientific facts and interesting features surrounding worlds with photos and videos.

The solar system is home to 8 planets: Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus and Neptune. The first 4 belong to the inner solar system and are considered terrestrial planets. Jupiter and Saturn are the large planets of the solar system and representatives of the gas giants (huge and filled with hydrogen and helium), and Uranus and Neptune are ice giants (large and represented by heavier elements).

Previously, Pluto was considered the ninth planet, but since 2006 it has become a dwarf planet. This dwarf planet was first discovered by Clyde Tomb. It is now one of the largest objects in the Kuiper Belt, a collection of icy bodies on the outer edge of our system. Pluto lost its planetary status after the IAU (International Astronomical Union) revised the concept itself.

According to the IAU decision, a solar system planet is a body that performs an orbital passage around the Sun, endowed with sufficient mass to form into a sphere and clear the area around it of foreign objects. Pluto failed to meet the latter requirement, which is why it became a dwarf planet. Other similar objects include Ceres, Makemake, Haumea and Eris.

With a small atmosphere, harsh surface features and 5 moons, Pluto is considered the most complex dwarf planet and one of the most amazing planets in our Solar System.

But scientists have not given up hope of finding the mysterious Planet Nine, after they announced in 2016 a hypothetical object that exerts its gravity on bodies in the Kuiper Belt. According to its parameters, it is 10 times the mass of the Earth and 5000 times more massive than Pluto. Below is a list of planets of the solar system with photos, names, descriptions, detailed characteristics and interesting facts for children and adults.

Variety of planets

Astrophysicist Sergei Popov about gas and ice giants, double star systems and single planets:

Hot planetary coronas

Astronomer Valery Shematovich on the study of gaseous shells of planets, hot particles in the atmosphere and discoveries on Titan:

Terrestrial planets of the solar system

The first 4 planets from the Sun are called terrestrial planets because their surface is rocky. Pluto also has a solid surface layer (frozen), but it is classified as a dwarf planet.

Gas giant planets of the solar system

There are 4 gas giants living in the outer solar system, as they are quite huge and gaseous. But Uranus and Neptune are different because they have more ice. That's why they are also called ice giants. However, all gas giants have one thing in common: they are all made of hydrogen and helium.

The IAU has put forward a definition of a planet:

• The object must be orbiting the Sun;
• Have sufficient mass to take the shape of a ball;
• Clear your orbital path of foreign objects;

Pluto could not meet the latter requirement, since it shares its orbital path with a huge number of Kuiper Belt bodies. But not everyone agreed with the definition. However, dwarf planets such as Eris, Haumea and Makemake appeared on the scene.

Ceres also lives between Mars and Jupiter. It was noticed in 1801 and considered a planet. Some still consider it the 10th planet of the solar system.

Dwarf planets of the solar system

Formation of planetary systems

Astronomer Dmitry Vibe about rocky planets and giant planets, the diversity of planetary systems and hot Jupiters:

Planets of the Solar System in order

The following describes the characteristics of the 8 main planets of the Solar System in order from the Sun:

The first planet from the Sun is Mercury

Mercury is the first planet from the Sun. Rotates in an elliptical orbit at a distance of 46-70 million km from the Sun. It takes 88 days for one orbital flight, and 59 days for an axial flight. Due to its slow rotation, a day spans 176 days. The axial tilt is extremely small.

With a diameter of 4887 km, the first planet from the Sun reaches 5% of the Earth's mass. Surface gravity is 1/3 of Earth's. The planet is practically devoid of an atmospheric layer, so it is hot during the day and freezes at night. The temperature ranges between +430°C and -180°C.

There is a crater surface and an iron core. But its magnetic field is inferior to that of the earth. Initially, radar indicated the presence of water ice at the poles. The Messenger apparatus confirmed the assumptions and found deposits at the bottom of craters, which are always immersed in shadow.

The first planet from the Sun is located close to the star, so it can be seen before dawn and just after sunset.

• Title: Messenger of the gods in the Roman pantheon.
• Diameter: 4878 km.
• Orbit: 88 days.
• Length of day: 58.6 days.

The second planet from the Sun is Venus

Venus is the second planet from the Sun. Travels in an almost circular orbit at a distance of 108 million km. It comes closest to Earth and can reduce the distance to 40 million km.

The orbital path takes 225 days, and the axial rotation (clockwise) lasts 243 days. A day spans 117 Earth days. The axial tilt is 3 degrees.

In diameter (12,100 km), the second planet from the Sun is almost identical to the Earth’s and reaches 80% of the Earth’s mass. The gravity indicator is 90% of Earth's. The planet has a dense atmospheric layer, where the pressure is 90 times higher than Earth's. The atmosphere is filled with carbon dioxide with thick sulfur clouds, creating a powerful greenhouse effect. It is because of this that the surface warms up by 460°C (the hottest planet in the system).

The surface of the second planet from the Sun is hidden from direct observation, but scientists were able to create a map using radar. Covered by large volcanic plains with two huge continents, mountains and valleys. There are also impact craters. A weak magnetic field is observed.

• Discovery: The ancients saw without the use of tools.
• Name: Roman goddess responsible for love and beauty.
• Diameter: 12104 km.
• Orbit: 225 days.
• Day length: 241 days.

The third planet from the Sun is Earth

Earth is the third planet from the Sun. It is the largest and densest of the inner planets. The orbital path is 150 million km away from the Sun. It has a single companion and developed life.

The orbital flyby takes 365.25 days, and the axial rotation takes 23 hours, 56 minutes and 4 seconds. The length of the day is 24 hours. The axial tilt is 23.4 degrees, and the diameter is 12742 km.

The third planet from the Sun was formed 4.54 billion years ago and for most of its existence the Moon was nearby. It is believed that the satellite appeared after a huge object crashed into the Earth and tore material into orbit. It is the Moon that stabilizes the Earth's axial tilt and acts as the source of the formation of tides.

The satellite's diameter covers 3,747 km (27% of Earth's) and is located at a distance of 362,000-405,000 km. Experiencing planetary gravitational influence, due to which it slowed down its axial rotation and fell into a gravitational block (therefore, one side is turned towards the Earth).

The planet is protected from stellar radiation by a powerful magnetic field formed by the active core (molten iron).

• Diameter: 12760 km.
• Orbit: 365.24 days.
• Day length: 23 hours and 56 minutes.

The fourth planet from the Sun is Mars

Mars is the fourth planet from the Sun. The Red Planet moves along an eccentric orbital path - 230 million km. One flight around the Sun takes 686 days, and an axial revolution takes 24 hours and 37 minutes. It is located at an inclination of 25.1 degrees, and the day lasts 24 hours and 39 minutes. Its inclination resembles that of the Earth, which is why it has seasons.

The diameter of the fourth planet from the Sun (6792 km) is half that of Earth, and its mass reaches 1/10 of Earth’s. Gravity indicator – 37%.

Mars is deprived of protection as magnetic field, so the original atmosphere was destroyed by the solar wind. The devices recorded the outflow of atoms into space. As a result, the pressure reaches 1% of the earth's, and the thin atmospheric layer is represented by 95% carbon dioxide.

The fourth planet from the Sun is extremely frosty, with temperatures dropping to -87°C in winter and rising to -5°C in summer. This is a dusty place with giant storms that can cover the entire surface.

• Discovery: The ancients saw without the use of tools.
• Name: Roman god of war.
• Diameter: 6787 km.
• Orbit: 687 days.
• Day length: 24 hours and 37 minutes.

The fifth planet from the Sun is Jupiter

Jupiter is the fifth planet from the Sun. In addition, this is the largest planet in the system, which is 2.5 times more massive than all the planets and covers 1/1000 of the solar mass.

It is distant from the Sun by 780 million km and spends 12 years on its orbital path. Filled with hydrogen (75%) and helium (24%) and may have a rocky core immersed in liquid metallic hydrogen with a diameter of 110,000 km. The total planetary diameter is 142984 km.

In the upper layer of the atmosphere there are 50-kilometer clouds, represented by ammonia crystals. They are in bands moving at different speeds and latitudes. The Great Red Spot, a large-scale storm, seems remarkable.

The fifth planet from the Sun spends 10 hours on its axial rotation. This is a rapid speed, which means the equatorial diameter is 9000 km larger than the polar one.

• Discovery: The ancients saw without the use of tools.
• Name: the main god in the Roman pantheon.
• Diameter: 139822 km.
• Orbit: 11.9 years.
• Length of day: 9.8 hours.

The sixth planet from the Sun is Saturn

Saturn is the sixth planet from the Sun. Saturn is in 2nd position in terms of scale in the system, exceeding the Earth's radius by 9 times (57,000 km) and 95 times more massive.

It is distant from the Sun by 1400 million km and spends 29 years on its orbital flight. Filled with hydrogen (96%) and helium (3%). May have a rocky core in liquid metallic hydrogen with a diameter of 56,000 km. The upper layers are represented by liquid water, hydrogen, ammonium hydrosulfide and helium.

The core is heated to 11,700°C and produces more heat than the planet receives from the Sun. The higher we rise, the lower the degree drops. At the top, the temperature is maintained at -180°C and 0°C at a depth of 350 km.

The cloud layers of the sixth planet from the Sun resemble the picture of Jupiter, but they are fainter and wider. There is also the Great White Spot, a brief periodic storm. It takes 10 hours and 39 minutes to complete an axial rotation, but exact figure It is difficult to name, since there are no fixed surface features.

• Discovery: The ancients saw without the use of tools.
• Name: god of the economy in the Roman pantheon.
• Diameter: 120500 km.
• Orbit: 29.45 days.
• Length of day: 10.5 hours.

The seventh planet from the Sun is Uranus

Uranus is the seventh planet from the Sun. Uranus is a representative of the ice giants and is the 3rd largest in the system. Its diameter (50,000 km) is 4 times greater than that of Earth and 14 times more massive.

It is distant by 2900 million km and spends 84 years on its orbital path. What’s surprising is that the planet’s axial tilt (97 degrees) literally rotates on its side.

It is believed that there is a small rocky core around which a mantle of water, ammonia and methane is concentrated. This is followed by a hydrogen, helium and methane atmosphere. The seventh planet from the Sun also stands out in that it does not radiate more internal heat, so the temperature mark drops to -224°C (the coldest planet).

• Discovery: In 1781, noticed by William Herschel.
• Name: personification of the sky.
• Diameter: 51120 km.
• Orbit: 84 years.
• Duration of the day: 18 hours.

Neptune is the eighth planet from the Sun. Neptune has been considered the official last planet in the solar system since 2006. The diameter is 49,000 km, and its massiveness is 17 times greater than that of Earth.

It is distant by 4500 million km and spends 165 years on an orbital flight. Due to its remoteness, the planet receives only 1% of solar radiation (compared to Earth). The axial tilt is 28 degrees, and the rotation takes 16 hours.

The meteorology of the eighth planet from the Sun is more pronounced than that of Uranus, so powerful storm activity can be seen at the poles in the form of dark spots. The wind accelerates to 600 m/s, and the temperature drops to -220°C. The core heats up to 5200°C.

• Discovery: 1846
• Name: Roman god of water.
• Diameter: 49530 km.
• Orbit: 165 years.
• Duration of the day: 19 hours.

This is a small world, smaller in size than Earth's satellite. The orbit intersects with Neptune in 1979-1999. it could be considered the 8th planet in terms of distance from the Sun. Pluto will remain beyond Neptune's orbit for more than two hundred years. The orbital path is inclined to the system plane at 17.1 degrees. Frosty World visited New Horizons in 2015.

• Discovery: 1930 - Clyde Tombaugh.
• Name: Roman god of the underworld.
• Diameter: 2301 km.
• Orbit: 248 years.
• Length of day: 6.4 days.

Planet Nine is a hypothetical object residing in the outer system. Its gravity should explain the behavior of trans-Neptunian objects.

Its existence was first announced by Chad Trujillo and Scott Sheppard in 2014. In 2016, they were supported by Konstantin Batygin and Michael Brown. The predicted object should reach 10 Earth masses, and the orbital period should be 15,000 years.

The planet has not yet been found and is difficult to detect due to its supposed remoteness. The theory has many supporters, but there are also desperate skeptics looking for other explanations. On our website you will find all the most interesting information about the planets of the solar system for children and adults. The upper table shows the distances from the Sun to the planets in order. You can find out not only how many planets are in the solar system, but also get their maximum characteristics from a photo of the surface.

Useful articles.

Pluto By decision of the MAC (International Astronomical Union) it no longer belongs to the planets of the Solar System, but is a dwarf planet and is even inferior in diameter to another dwarf planet Eris. Pluto's designation is 134340.

solar system

Scientists put forward many versions of the origin of our solar system. In the forties of the last century, Otto Schmidt hypothesized that the solar system arose because cold dust clouds were attracted to the Sun. Over time, clouds formed the foundations of future planets. IN modern science It is Schmidt's theory that is fundamental. The solar system is only a small part of a large galaxy called the Milky Way. The Milky Way contains more than one hundred billion different stars. It took humanity thousands of years to realize such a simple truth. The discovery of the solar system did not happen immediately; step by step, based on victories and mistakes, a system of knowledge was formed. The main basis for studying the solar system was knowledge about the Earth.

Fundamentals and Theories

The main milestones in the study of the solar system are the modern atomic system, the heliocentric system of Copernicus and Ptolemy. The most probable version of the origin of the system is considered to be the Big Bang theory. In accordance with it, the formation of the galaxy began with the “scattering” of the elements of the megasystem. At the turn of the impenetrable house, our Solar system was born. The basis of everything is the Sun - 99.8% of the total volume, the planets account for 0.13%, the remaining 0.0003% are the various bodies of our system. Scientists have accepted the division of planets into two conditional groups . The first includes planets of the Earth type: the Earth itself, Venus, Mercury. The main distinguishing characteristics of the planets of the first group are their relatively small area, hardness, and a small number of satellites. The second group includes Uranus, Neptune and Saturn - they are distinguished big sizes(giant planets), they are formed by helium and hydrogen gases.

In addition to the Sun and planets, our system also includes planetary satellites, comets, meteorites and asteroids.

Particular attention should be paid to the asteroid belts, which are located between Jupiter and Mars, and between the orbits of Pluto and Neptune. On this moment In science there is no unambiguous version of the origin of such formations.
Which planet is not currently considered a planet:

From the time of its discovery until 2006, Pluto was considered a planet, but later many celestial bodies were discovered in the outer part of the Solar System, comparable in size to Pluto and even larger than it. To avoid confusion, a new definition of planet was given. Pluto did not fall under this definition, so it was given a new “status” - a dwarf planet. So, Pluto can serve as an answer to the question: it used to be considered a planet, but now it is not. However, some scientists continue to believe that Pluto should be reclassified back to a planet.

Scientists' forecasts

Based on research, scientists say that the sun is approaching the middle of its life path. It is unimaginable to imagine what will happen if the Sun goes out. But scientists say this is not only possible, but also inevitable. The age of the Sun was determined using the latest computer developments and it was found that it is about five billion years old. According to astronomical law, the life of a star like the Sun lasts about ten billion years. Thus, our solar system is in the middle of its life cycle. What do scientists mean by the word “will go out”? Huge solar energy represents the energy of hydrogen, which becomes helium at the core. Every second, about six hundred tons of hydrogen in the Sun's core are converted into helium. According to scientists, the Sun has already used up most of its hydrogen reserves.

If instead of the Moon there were planets of the solar system:

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.

Terrestrial planets: And . These planets are small in size with a rocky surface and are closest to the Sun.

Giant planets: And . This major planets, consisting mainly of gas and characterized by the presence of rings consisting of icy dust and many rocky pieces.

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 most great companion 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. Interesting fact that the Triton satellite has a reverse direction of orbital motion; strange volcanoes were also discovered on the satellite, which 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...