5 largest planets. The largest planets in the solar system. Moon, Ganymede, Io, Deimos, Phobos and other satellites of the planets of the solar system

Planets of the Solar System

According to the official position of the International Astronomical Union (IAU), the organization that assigns names to astronomical objects, there are only 8 planets.

Pluto was removed from the planet category in 2006. because There are objects in the Kuiper belt that are larger/equal in size to Pluto. Therefore, even if we take it as a full-fledged celestial body, then it is necessary to add Eris to this category, which has almost the same size as Pluto.

By MAC definition, 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: terrestrial planets and 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 2440 km. The period of revolution around the Sun, equated to an earthly year for ease of understanding, is 88 days, while Mercury manages to rotate around its own axis only one and a half times. Thus, his day lasts approximately 59 Earth days. For a long time it was believed that this planet always turned the same side to the Sun, since periods of its visibility from Earth were repeated with a frequency approximately equal to four Mercury days. This misconception was dispelled with the advent of the ability to use radar research and conduct continuous observations using space stations. The orbit of Mercury is one of the most unstable; not only the speed of movement and its distance from the Sun change, but also the position itself. Anyone interested can observe this effect.

Mercury in color, image from the MESSENGER spacecraft

Its proximity to the Sun is the reason why Mercury is subject to the largest temperature changes among the planets in our system. The average daytime temperature is about 350 degrees Celsius, and the nighttime temperature is -170 °C. Sodium, oxygen, helium, potassium, hydrogen and argon were detected in the atmosphere. There is a theory that it was previously a satellite of Venus, but so far this remains unproven. It does not have its own satellites.

Venus

The second planet from the Sun, the atmosphere 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 to become visible after sunset, just as before dawn it continues to be visible even when all the other stars have disappeared from view. The percentage of carbon dioxide in the atmosphere is 96%, there is relatively little nitrogen in it - almost 4%, and water vapor and oxygen are present in very small quantities.

Venus in the UV spectrum

Such an atmosphere creates a greenhouse effect; the temperature on the surface is even higher than that of Mercury and reaches 475 °C. Considered the slowest, a Venusian day lasts 243 Earth days, which is almost equal to a year on Venus - 225 Earth days. Many call it Earth's sister because of its mass and radius, the values ​​of which are very close to those of Earth. The radius of Venus is 6052 km (0.85% of Earth's). Like Mercury, there are no satellites.

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 have developed. At least life as we know it. The radius of the Earth is 6371 km and, unlike other celestial bodies in 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 changes 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 a complete passage through the orbit lasts 365 days, which is much longer in comparison with its closest neighboring planets. The Earth's day and year are also accepted as a standard, but this is done only for the convenience of perceiving time periods on other planets. The Earth has one natural satellite - the Moon.

Mars

The fourth planet from the Sun, known for its thin atmosphere. Since 1960, Mars has been actively explored by scientists from several countries, including the USSR and the USA. Not all exploration programs have been successful, but water found at some sites suggests that primitive life exists on Mars, or existed in the past.

The brightness of this planet allows it to be seen from Earth without any instruments. Moreover, once every 15-17 years, during the Confrontation, it becomes the brightest object in the sky, eclipsing even Jupiter and Venus.

The radius is almost half that of Earth and is 3390 km, but the year is much longer - 687 days. He has 2 satellites - Phobos and Deimos .

Visual model of the solar system

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• Sun

  The Sun is a star that is a hot ball of hot 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 throughout the Milky Way galaxy.

• Mercury

  Sun-scorched Mercury is only slightly larger than Earth's satellite the Moon. Like the Moon, Mercury is practically devoid of an atmosphere and cannot smooth out the traces of impact from falling meteorites, so it, like the Moon, is covered with craters. The day side of Mercury gets very hot from 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 completes 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 by a thick and toxic atmosphere that creates a strong greenhouse effect. This scorched world is hot enough to melt lead. Radar images through the powerful atmosphere revealed volcanoes and deformed 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, atmospheres, seasons and even weather, but only on Earth did all these components come together in a way that made life possible.

• Mars

  Although details of the surface of Mars are difficult to see from Earth, observations through a telescope indicate 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, that Mars might be a suitable place for life, and that water existed in the polar ice caps. When the Mariner 4 spacecraft arrived at Mars in 1965, many scientists were shocked to see photographs of the murky, cratered planet. Mars turned out to be a dead planet. More recent missions, however, have revealed that Mars holds many mysteries that 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 become a full-fledged star, Jupiter needed to become 80 times more massive.

• Saturn

  Saturn is the farthest of the five planets known before the invention of the telescope. Like Jupiter, Saturn is composed primarily of hydrogen and helium. Its volume is 755 times greater than that of the Earth. Winds in its atmosphere reach speeds of 500 meters per second. These fast winds, combined with heat rising from the planet's interior, cause the yellow and golden streaks we see in the atmosphere.

• Uranus

  The first planet found using 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

  Distant Neptune rotates almost 4.5 billion kilometers from the Sun. It takes him 165 years to complete one revolution around the Sun. It is invisible to the naked eye due to its vast distance from Earth. Interestingly, 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 was long considered the ninth planet. But after discoveries of Pluto-like worlds that were even further away, Pluto was reclassified as a dwarf planet in 2006.

Planets are giants

There are four gas giants located beyond the orbit of Mars: Jupiter, Saturn, Uranus, Neptune. They are located 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 planet 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, lasting 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.

There is an opinion that one of the four gas giants is actually a failed star. This theory is also 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, you need a fairly accurate and clear model of the solar system. The largest of them are Callisto, Ganymede, Io and Europa. Moreover, Ganymede is the largest satellite of the planets in the entire solar system, its radius is 2634 km, which is 8% greater than the size of Mercury, the smallest planet in our system. Io has the distinction of being one of only three moons with an atmosphere.

Saturn

The second largest planet and the sixth in the solar system. In comparison with other planets, it is most similar to the Sun in the composition of chemical elements. The radius of the surface is 57,350 km, the year is 10,759 days (almost 30 Earth years). A day here lasts a little longer than on Jupiter - 10.5 Earth hours. In terms of the number of satellites, it is not much behind its neighbor - 62 versus 67. The largest satellite of Saturn is Titan, just like Io, which is distinguished by the presence of an atmosphere. Slightly smaller in size, but no less famous are 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 others.

For a long time, the rings on Saturn were considered a unique phenomenon unique to it. Only recently it was established that all gas giants have rings, but in others they are not so clearly visible. Their origin has not yet been established, although there are several hypotheses about how they appeared. In addition, it was recently discovered that Rhea, one of the satellites of the sixth planet, also has some kind of rings.

Today, scientists know only one large solar system in which our planet is located. It was formed 4.6 billion years ago. Stellar clouds of matter began to thicken in the Galaxy. Because of this, a large amount of thermal energy gradually began to be generated. With the formation of high temperature and density, nuclear reactions began to form, which provoked the formation of various gases and helium. These flows triggered the formation of the star we now call the Sun. The process of its creation took about several tens of millions of years.

Due to the high temperature, star dust accumulated in dense compounds, forming individual planets with its structure. Since the formation of all the planets and satellites of the solar system, no significant changes have been observed.

Heliocentric theory of world construction

In the second century AD, a scientist from Alexandria put forward a hypothesis about the location of our planet. It was from this that all scientists started, until the end of the fifteenth century. According to his theory, our planet was at the very center of the universe, and all other planets, including the Sun, could only rotate around its axis. But only thanks to the painstaking work of Nicolaus Copernicus, this hypothesis suffered a crushing failure. His observations were published only after his death, so the astronomer never received world recognition. His observations were able to prove the fact that the Sun is the center of the system, and all other planets can revolve around it along a given trajectory.

Number of planets in the solar system

Everyone knows that at the moment there are eight planets in the solar system. But until recently, it was believed that Pluto, which was discovered in early 1930, was also part of the solar system. But after much observation and research, it turned out that the planet farthest from the Sun does not rotate along a given trajectory at all. She is constantly in one position and does not move at all. Only with the onset of 2006, at the International Assembly in Prague, was it possible to prove that the dwarf planet is not part of the solar system at all.

The principle of the largest solar system

It is worth noting that the solar system is part of the milky way, which is located in our Galaxy. It is located on its outskirts, and is located at a distance of thirty thousand light years from its central point. The solar system includes the Sun itself, as well as numerous planets, satellites and asteroids that constantly move along a given trajectory.

Planet placement

All planets are divided into two different types. These are the inner and outer planets. The first type includes the four planets that are closest to the surface of the Sun. This:

Mercury;

Their sizes in relation to other planets are not so large, and the surface is covered with a rocky hard crust.

The second type includes giant planets:

These are those planets that mainly consist of a collection of various gases. They are located almost in the same plane. From the North Pole, you can clearly see that the planets move around the Sun in a direction that is opposite to the clockwise movement.

But be that as it may, there are always unexplored areas of space in the universe that can hide huge secrets. Perhaps in a few decades, scientists will be able to reach the most hidden corners.

When people say “the largest planet,” Jupiter immediately comes to mind. Yes, this giant is more than 11 times larger in diameter than the Earth, and 317 times heavier. The Earth, compared to this planet, is just a dwarf, suitable only as a satellite. Of course, he is the king in our solar system, only the Sun is bigger than him. However, everything in the world is relative.

Therefore, Jupiter is not at all the largest planet known to science. After all, thousands of planets have now been discovered around other stars, and among them there are some very strange and remarkable ones. Each such planet is a world unlike the others, and a separate article can be written about each of them.

Until recently, the record holder for size was the planet Tres-4b, located in the constellation Hercules. From 2006 to 2011, it was the largest planet in the Universe. It is 1.706 times larger than Jupiter, almost twice. What is curious is that this planet is located in a binary system, and no other similar ones are yet known, because in such systems the gravitational forces of two stars act, preventing the formation of planets and stable orbits.

Planet Tres-4b is a gas giant similar to Jupiter and is located very close to its star - only 4.5 million kilometers. For comparison, the distance from the Sun to Mercury, the hottest planet in our system, is 58 million kilometers, and to Earth – 150 million!

Tres-4b completes a full orbit in just 3.5 days, and this ball of gas is very hot - its temperature exceeds 1700 degrees. Hot gas tends to expand, so this planet is “loose”, its density is very low, on average, like that of polystyrene foam or balsa wood. This is very little.

Although Tres-4b is a large planet, its mass is slightly less than that of Jupiter, and therefore its gravity is less. This hot gas planet, with its large size and low gravity, is not able to retain its substance, so it constantly loses it from its atmosphere. This gas plume trails behind the planet like a comet's tail.

This planet is a mystery to scientists. With such a gigantic size and disproportionately small mass, it simply should not exist. Yes, now it is losing mass, but how could it even form under such conditions? Maybe it was once not so hot, and therefore was smaller and more dense, like Jupiter? Then in the past it was much further from the star or was completely captured by the star somewhere along the way.

Unfortunately, it is not possible to look at this planet live in the foreseeable future - the distance to it is unimaginably large, 1600 light years.

This huge planet was discovered by the transit method back in 2006, and the results were published a year later.

The program within which the research was carried out is called TrES - Trans-Atlantic Exoplanet Survey, or Trans-Atlantic Exoplanet Survey. It involves three small 10-centimeter telescopes from different observatories, equipped with Schmidt cameras and auto-search. A total of five exoplanets were discovered as part of this program, including Tres-4b.

The largest planet in the Universe – HAT-P-32b

In 2011, the new largest planet in the Universe was discovered, which turned out to be larger than Tres-4b. It is located in the constellation Andromeda, at a distance of 1044 light years from us.

This planet has a radius of 2.037 times Jupiter, making it slightly larger than Tres-4b. But its mass is approximately the same, and slightly less than Jupiter’s. In other respects, HAT-P-32b is very similar to Tres-4b.

This planet is also a hot ball of gas, even hotter. Its temperature reaches 1888 degrees. This planet is also located close to the star - at a distance of about 5 million kilometers, and due to its enormous temperature, its gas also expands and is lost. Therefore, its density is also low.

Scientists are constantly discovering new planets around other stars, and it is possible that this record will be broken, and soon we will learn about the other largest planet in the Universe.

Among the planets of the Solar System there are many gas giants that amaze the imagination with their size. These are Jupiter, Uranus and Neptune. Next to them, our Earth is just a dwarf. But which planet in the solar system is the largest? Of course, this is Jupiter, which the ancient Romans named after their main god for a reason. Moreover, it is 2.5 times heavier than all the other planets, even if they are all piled up against it alone.

Jupiter is a huge ball of gas. It is the fifth planet of the Solar System, its orbit is located beyond the orbit, after the asteroid belt.

The diameter of Jupiter at the equator is 143 thousand kilometers, versus 12,742 for the Earth - it is 11 times larger. All other gas giants, although huge, are much smaller. The second largest planet is Saturn, with a diameter of 120 thousand kilometers, two Earth diameters less.

The mass of this largest planet is enormous - 1.9 * 10 27 kg. It's hard to imagine, so imagine 318 planet Earths dumped into one pile - they would weigh the same as Jupiter alone. But the Sun is even larger - it weighs as much as 1050 Jupiters.

The area of ​​the largest planet is 122 times larger than that of Earth. But we must keep in mind that the surface of Jupiter is a relative concept, since it simply is not there. As it goes down, the gas simply gradually becomes denser until it first turns into a liquid and then into a metallic state.

However, Jupiter is the largest only in our solar system. The largest planet among all known to scientists is twice its size. This is which is located in the constellation Andromeda.

Moons of Jupiter

Jupiter is not alone - dozens of satellites orbit around it. Now there are 79 of them known, of various shapes and sizes. One of them is Ganymede, the largest moon in the solar system. There are also very small ones, which are simply asteroids, pieces of stone or ice of irregular shape.

The largest and most famous satellites are called Galilean, named after Galileo Galilei who discovered them. In addition to Ganymede, these include Callisto. They can be seen near the planet even with binoculars.

Jupiter is not only the largest planet in the solar system, but also the most massive. It has powerful gravity, which affects many distant cosmic bodies. This giant can easily capture an asteroid flying by or deflect its trajectory. But he can also throw him into space. Therefore, the number of Jupiter’s satellites changes - sometimes new ones are added and old ones, usually small ones, disappear. Large satellites rotate in stable orbits, and each of them is unique in its own way.

Largely thanks to the gravity of this largest planet, we are still alive. , like a watchdog, “catch” most of the large asteroids and comets heading to the inner part of the solar system, where our Earth is located. It changes their path to a safer one for us, so very few of these space guests reach us. Otherwise, the Earth would regularly experience global Armageddon with worldwide extinction.

The atmosphere of the largest planet in the solar system

This planet has a very powerful atmosphere, because it is a gas giant. It is also larger than that of other planets, and consists mainly of hydrogen and helium. Methane, ammonia, hydrogen sulfide and water are present in small quantities.

Jupiter does not have a surface in the usual sense. On Earth there is air, and there is a solid surface. On Jupiter we could descend for a very long time, and the pressure would increase. Gradually the gas would turn into a mist, then pass into an intermediate semi-liquid state, then into a liquid. Diving further into the ocean of liquid hydrogen, we would observe its compaction down to the metallic state. But there is no clear boundary where this happens, since the substance also goes through intermediate stages. The boundary of the atmosphere is located at an altitude of 5000 kilometers from the conventional surface - where hydrogen is already liquid.

The atmosphere of Jupiter is very stormy, there are a lot of vortices and hurricanes of different sizes. The largest hurricane in the solar system is the Great Red Spot, which can be seen even with an average amateur telescope. This hurricane has been raging for several centuries, although it has diminished recently.

Comparative sizes of the Great Red Spot on Jupiter.

The bands visible on Jupiter are formed by many clouds twisted into bizarre spirals by strong winds - they are called belts and move in different directions. The clouds themselves consist of water, ammonia crystals, and ammonium sulfide, so they have different colors and are located at different heights. And among them powerful lightning strikes, which are incomparable with those on earth.

Can Jupiter become a star?

The largest planet in the solar system is huge. For a long time it was believed that Jupiter lacked just a little mass for a thermonuclear reaction to begin in its depths and it to become a star. Indeed, the planet produces more energy, including heat, than it receives from the Sun. But this happens due to compression and enormous pressure in its deep layers. By the way, this is why it has such a stormy atmosphere.

Jupiter is shrinking by 2 centimeters per year. It is believed that it was originally twice as large as it is now, and much hotter. Exoplanets are now known that are several times larger than it.

But Jupiter will never become a star - it is huge compared to other planets, but too small for a star. It needs to become 75 times more massive to become a star. But its size will change little because of this - such a mass will be very dense, and a thermonuclear reaction will begin in the center.

To gain sufficient mass, Jupiter simply does not have enough matter in the solar system. Even if it absorbs all the other planets, all the asteroids and comets, it will not be enough. Therefore, it will always be a planet, and the largest one at that.