On March 13, 1781, English astronomer William Herschel discovered the seventh planet 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 satellites consists 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
On October 4, 1957, the world's first artificial Earth satellite was launched into low-Earth orbit. Thus began the space age in human history. Since then, artificial satellites have been regularly helping to study the cosmic bodies of our galaxy.
Artificial Earth satellites (AES)
In 1957, the USSR was the first to launch a satellite into low-Earth orbit. The United States was the second to do this, a year later. Later, many countries launched their satellites into Earth orbit - however, satellites purchased from the USSR, USA or China were often used for this. Nowadays satellites are launched even by radio amateurs. However, many satellites have important tasks: astronomical satellites explore the galaxy and space objects, biosatellites help conduct scientific experiments on living organisms in space, meteorological satellites help predict the weather and observe the Earth's climate, and the tasks of navigation and communication satellites are clear from their names. Satellites can be in orbit from several hours to several years: for example, manned spacecraft can become a short-term artificial satellite, and a space station can become a long-term spacecraft in Earth orbit. In total, more than 5,800 satellites have been launched since 1957, 3,100 of them are still in space, but of these three thousand, only about one thousand are operational.
Artificial lunar satellites (ALS)
At one time, ISLs were very helpful in studying the Moon: when entering its orbit, satellites photographed the lunar surface in high resolution and sent pictures to Earth. In addition, by changing the trajectory of the satellites, it was possible to draw conclusions about the gravitational field of the Moon, the features of its shape and internal structure. Here Soviet Union again ahead of everyone: in 1966, the Soviet automatic station Luna-10 was the first to enter lunar orbit. And over the next three years, 5 more Soviet satellites of the Luna series and 5 American satellites of the Lunar Orbiter series were launched.
Artificial satellites of the Sun
It is curious that until the 1970s, artificial satellites appeared near the Sun... by mistake. The first such satellite was Luna 1, which missed the Moon and entered the orbit of the Sun. And this despite the fact that switching to a heliocentric orbit is not so easy: the device must gain a second escape velocity, without exceeding the third. And when approaching planets, the device can slow down and become a satellite of the planet, or speed up and completely leave the solar system. But NASA satellites orbiting the Sun near the Earth’s orbit began to take detailed measurements of the solar wind parameters. The Japanese satellite observed the Sun in X-rays for about ten years - until 2001. Russia launched a solar satellite in 2009: Coronas-Photon will explore the most dynamic solar processes and monitor around the clock solar activity to predict geomagnetic disturbances.
Artificial satellites of Mars (ISM)
First artificial satellites Mars became... three ISMs at once. Two space probes were launched by the USSR (“Mars-2” and “Mars-3”) and another by the USA (“Mariner-9”). But the point is not that the launch was a “race” and there was such an overlap: each of these satellites had its own task. All three ISMs were launched into significantly different elliptical orbits and performed different scientific research, complementing each other. Mariner 9 produced a map of the surface of Mars for mapping, and Soviet satellites studied the characteristics of the planet: the flow of solar wind around Mars, the ionosphere and atmosphere, topography, temperature distribution, the amount of water vapor in the atmosphere and other data. In addition, Mars 3 was the first in the world to make a soft landing on the surface of Mars.
Artificial Satellites of Venus (ASV)
The first WIS were again Soviet spacecraft. Venera 9 and Venera 10 entered orbit in 1975. Having reached the planet. They were divided into satellites and devices lowered to the planet. Thanks to WIS radar, scientists were able to obtain radio images from high degree details, and the devices that softly descended to the surface of Venus took the world's first photographs of the surface of another planet... The third satellite was the American Pioneer Venera 1 - it was launched three years later.
The solar system consists of eight planets and more than 63 of their satellites, which are being discovered more and more often, as well as several dozen comets and a large number of asteroids. All cosmic bodies move along their own clearly directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the Solar System combined.
How many planets revolve around the sun
How did the planets of the solar system originate: approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy ( milky way), having the shape of a disk, began to shrink towards the center, little by little forming the present Sun. Further, according to one theory, 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. As another theory says, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and became denser, forming the current planets. Now 8 planets revolve around the Sun constantly.
The center of the solar system is the Sun, a star around which the planets orbit. 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. Let us briefly list them all in order of distance from the sun. And now a few definitions.
Satellites of the planets. The solar system also includes the Moon and the natural satellites of other planets, which they all have except Mercury and Venus. Over 60 satellites are known. Most of the satellites of the outer planets were discovered when they received photographs taken by robotic spacecraft. Jupiter's smallest satellite, Leda, is only 10 km across.
The sun is a star without which life on Earth could not exist. It 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 of 1,392,000 km, 109 times larger than that of 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, approximately 332,950 times the mass of the Earth. The temperature inside the core is approximately 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius.
By chemical composition The sun is made up of 75% hydrogen, and the other 25% elements are mostly helium. Now let’s figure out in order how many planets revolve around the sun, in the solar system and the characteristics of the planets.
Planets of the solar system in order from the sun
in pictures
Mercury is the 1st planet in the solar system
Mercury. The four inner planets (closest to the Sun)—Mercury, Venus, Earth, and Mars—have a rocky surface. They are smaller than the four giant planets. Mercury moves faster than other planets, being burned by the sun's rays during the day and freezing at night.
Characteristics of the planet Mercury:
Period of revolution around the Sun: 87.97 days.
Diameter at the equator: 4878 km.
Rotation period (rotation around an axis): 58 days.
Surface temperature: 350 during the day and -170 at night.
Atmosphere: very rarefied, helium.
How many satellites: 0.
The main satellites of the planet: 0.
Venus is the 2nd planet in the solar system
Venus is more similar to Earth in size and brightness. Observing it is difficult due to the clouds enveloping it. The surface is a hot rocky desert.
Characteristics of the planet Venus:
Period of revolution around the Sun: 224.7 days.
Diameter at the equator: 12104 km.
Rotation period (rotation around an axis): 243 days.
Surface temperature: 480 degrees (average).
Atmosphere: dense, mostly carbon dioxide.
How many satellites: 0.
The main satellites of the planet: 0.
Earth is the 3rd planet in the solar system
Apparently, the Earth was formed from a gas and dust cloud, like other planets in the solar system. Particles of gas and dust collided and gradually “grew” the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled and became covered with a hard rock crust. But the temperature in the depths is still quite high - 4500 degrees. Rocks melted in the depths and poured out to the surface during volcanic eruptions. Only on earth there is water. That's 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.
Characteristics of planet Earth:
Period of revolution around the Sun: 365.3 days.
Diameter at the equator: 12756 km.
Period of rotation of the planet (rotation around its 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.
Mars is the 4th planet in the solar system
Because of its resemblance to Earth, it was believed that life existed here. But the spacecraft that descended to the surface of Mars found no signs of life. This is the fourth planet in order.
Characteristics of the planet Mars:
Period of revolution around the Sun: 687 days.
Diameter of the planet at the equator: 6794 km.
Rotation period (rotation around an axis): 24 hours 37 minutes.
Surface temperature: -23 degrees (average).
The planet's atmosphere: thin, mostly carbon dioxide.
How many satellites: 2.
The main satellites in order: Phobos, Deimos.
Jupiter is the 5th planet in the solar system
Jupiter, Saturn, Uranus and Neptune are made of hydrogen and other gases. Jupiter exceeds Earth by more than 10 times in diameter, 300 times in mass and 1300 times in volume. It is more than twice as massive as all the planets in the solar system combined. How long does it take for planet Jupiter to become a star? We need to increase its mass by 75 times!
Characteristics of the planet Jupiter:
Period of revolution around the Sun: 11 years 314 days.
Diameter of the planet at the equator: 143884 km.
Rotation period (rotation around an axis): 9 hours 55 minutes.
Planet surface temperature: -150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.
Saturn is the 6th planet in the solar system
It is number 2, the largest of the planets in the solar system. Saturn attracts attention thanks to its ring system formed of ice, rocks and dust that orbit the planet. There are three main rings with an outer diameter of 270,000 km, but their thickness is about 30 meters.
Characteristics of the planet Saturn:
Period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (rotation around an axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.
Uranus is the 7th planet in the solar system
A unique planet in the solar system. Its peculiarity is that it rotates around the Sun not like everyone else, but “lying on its side.” Uranus also has rings, although they are harder to see. In 1986, Voyager 2 flew at a distance of 64,000 km and had six hours of photography time, which it successfully completed.
Characteristics of the planet Uranus:
Orbital period: 84 years 4 days.
Diameter at the equator: 51118 km.
Period of rotation of the planet (rotation around its axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: Mainly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.
Neptune is the 8th planet in the solar system
At the moment, Neptune is considered the last planet in the solar system. Its discovery took place through mathematical calculations, and then it was seen through a telescope. In 1989, Voyager 2 flew by. He took stunning photographs of the blue surface of Neptune and its largest moon, Triton.
Characteristics of the planet Neptune:
Period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (rotation around an axis): 16 hours 7 minutes.
Surface temperature: -220 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 8.
Main satellites: Triton.
How many planets are there in the solar system: 8 or 9?
Previously, for many years, astronomers recognized the presence of 9 planets, that is, Pluto was also considered a planet, like the others already known to everyone. But in the 21st century, scientists were able to prove that it is not a planet at all, which means that there are 8 planets in the solar system.
Now, if you are asked how many planets are in the solar system, answer boldly - 8 planets in our system. This has been officially recognized since 2006. When arranging the planets of the solar system in order from the sun, use the ready-made picture. Do you think that maybe Pluto should not have been removed from the list of planets and that this is scientific prejudice?
How many planets are there in the solar system: video, watch for free
Natural satellites are relatively small cosmic bodies that orbit larger “host” planets. In part, an entire science is dedicated to them - planetology.
In the 70s, astronomers assumed that Mercury had several celestial bodies dependent on it, as they caught around ultraviolet radiation. It later turned out that the light belonged to a distant star.
Modern equipment allows us to study the planet closest to the Sun in more detail. Today, all planetary scientists in unison insist that it has no satellites.
Moons of the planet Venus
Venus is called Earth-like because they have similar compositions. But if we talk about natural space objects, then the planet named after the goddess of love is close to Mercury. These two planets in the solar system are unique in that they are completely alone.
Astrologers believe that Venus could have previously seen these, but to date not a single one has been discovered.
How many natural satellites does the Earth have?
Our native Earth has many satellites, but only one natural one, which every person knows about from infancy - this is the Moon.
The size of the Moon is more than a quarter of the diameter of the Earth and is 3475 km. She is the only one celestial body with such large dimensions relative to the “owner”.
Surprisingly, its mass is small - 7.35 × 10²² kg, which indicates low density. Multiple craters on the surface are visible from Earth even without any special devices.
What moons does Mars have?
Mars is a fairly small planet that is sometimes called red because of its scarlet hue. It is given by iron oxide, which is part of its composition. Today, Mars boasts two natural celestial objects.
Both moons, Deimos and Phobos, were discovered by Asaph Hall in 1877. They are the smallest and darkest objects in our comic system.
Deimos is translated as the ancient Greek god who spreads panic and terror. Based on observations, it is gradually moving away from Mars. Phobos, bearing the name of the god who brings fear and chaos, is the only satellite that is so close to the “master” (at a distance of 6000 km).
The surfaces of Phobos and Deimos are abundantly covered with craters, dust and various loose rocks.
Moons of Jupiter
Today, the giant Jupiter has 67 satellites - more than other planets. The largest of them are considered the achievement of Galileo Galilei, as they were discovered by him in 1610.
Among the celestial bodies orbiting Jupiter, it is worth noting:
- Adrasteus, with a diameter of 250 × 147 × 129 km and a mass of ~3.7 × 1016 kg;
- Metis - dimensions 60×40×35 km, weight ~2·1015 kg;
- Thebe, with a scale of 116×99×85 and a mass of ~4.4×1017 kg;
- Amalthea - 250×148×127 km, 2·1018 kg;
- Io with a weight of 9 1022 kg at 3660 × 3639 × 3630 km;
- Ganymede, which with a mass of 1.5·1023 kg had a diameter of 5263 km;
- Europe, occupying 3120 km and weighing 5·1022 kg;
- Callisto, with a diameter of 4820 km and a mass of 1·1023 kg.
The first satellites were discovered in 1610, some from the 70s to the 90s, then in 2000, 2002, 2003. The last of them were discovered in 2012.
Saturn and its moons
62 satellites have been found, of which 53 have names. Most of them consist of ice and rocks, characterized by a reflective feature.
The largest space objects of Saturn:
How many moons does Uranus have?
At the moment, Uranus has 27 natural celestial bodies. They are named after characters from famous works authored by Alexander Pope and William Shakespeare.
Names and list by quantity with description:
Moons of Neptune
The planet, whose name is similar to the name of the great god of the seas, was discovered in 1846. She was the first to be found using mathematical calculations, and not through observations. Gradually, new satellites were discovered until they counted 14.
List
Neptune's moons are named after nymphs and various sea deities from Greek mythology.
The beautiful Nereid was discovered in 1949 by Gerard Kuiper. Proteus is a non-spherical cosmic body and is studied in detail by planetary scientists.
Giant Triton is the iciest object in the solar system with a temperature of -240°C, and is also the only satellite that rotates around itself in the direction opposite to the rotation of the “master”.
Almost all of Neptune’s satellites have craters and volcanoes on their surface, both fire and ice. They spew from their depths mixtures of methane, dust, liquid nitrogen and other substances. Therefore, a person will not be able to stay on them without special protection.
What are “planetary satellites” and how many are there in the solar system?
Satellites are cosmic bodies that are smaller in size than the “host” planets and rotate in the orbits of the latter. The question of the origin of satellites is still open and is one of the key ones in modern planetology.
Today, 179 natural space objects are known, which are distributed as follows:
- Venus and Mercury – 0;
- Earth – 1;
- Mars – 2;
- Pluto – 5;
- Neptune – 14;
- Uranium – 27;
- Saturn – 63;
- Jupiter - 67.
Technology improves every year, finding more celestial bodies. Perhaps new satellites will be discovered soon. We can only wait, constantly checking the news.
The largest satellite in the solar system
The largest satellite in our solar system is Ganymede. giant Jupiter. Its diameter, according to scientists, is 5263 km. The next largest is Titan with a size of 5150 km - the “moon” of Saturn. The top three is closed by Callisto, the “neighbor” of Ganymede, with whom they share one “master”. Its scale is 4800 km.
Why do planets need satellites?
Planetologists have always asked the question “Why are satellites needed?” or “What effect do they have on the planets?” Based on observations and calculations, some conclusions can be drawn.
Natural satellites play an important role for the “hosts”. They create a certain climate on the planet. No less important is the fact that they serve as protection against asteroids, comets, and other dangerous celestial bodies.
Despite such a significant impact, satellites are still not necessary for the planet. Even without their presence, life can form and sustain on it. This conclusion was reached by the American scientist Jack Lissauer from the NASA Space Science Center.
Continuation. . .
The central star of our system, around which all the planets pass in different orbits, is called the Sun. Its age is about 5 billion years. It is a yellow dwarf, so the size of the star is small. It is not used up very quickly. The solar system has reached approximately the halfway point of its life cycle. After 5 billion years, the balance of gravitational forces will be disrupted, the star will increase in size and gradually warm up. converts all of the sun's hydrogen into helium. At this point, the size of the star will be three times larger. Ultimately, the star will cool down and shrink. Today the Sun consists almost entirely of hydrogen (90%) and some helium (10%).
Today, the satellites of the Sun are 8 planets, around which other celestial bodies revolve, several dozen comets, as well as a huge number of asteroids. All these objects move in their orbit. If you add up the mass of all the solar satellites, it turns out that they are 1000 times lighter than their star. The main celestial bodies of the system deserve detailed consideration.
General concept of the solar system
To consider the satellites of the Sun, you need to familiarize yourself with the definitions: what is a star, planet, satellite, etc. A star is a body that radiates light and energy into space. This is possible due to the thermonuclear reactions occurring in it and compression processes under the influence of gravity. There is only one star in our system - the Sun. There are 8 planets orbiting around it.
A planet today is a celestial body that revolves around a star and has a spherical (or close to it) shape. Such objects do not emit light (they are not a star). They can reflect it. Also, the planet does not have any other large celestial bodies near its orbit.
A satellite is an object that orbits another, larger star or planet. It is held in orbit by the gravitational force of this large celestial body. To understand how many satellites the Sun has, it should be noted that this list, in addition to planets, includes asteroids, comets, and meteorites. It is almost impossible to count them.
Planets
Until recently, it was believed that our system has 9 planets. After much discussion, Pluto was removed from this list. But he is also part of our system.
The 8 main planets are held in their orbits by the Sun. A satellite (planet) may also have celestial bodies orbiting around it. There are quite a few large objects. All planets are divided into 2 groups. The first includes the inner satellites of the Sun, and the second - the outer ones.
The planets of the terrestrial (first) group are as follows:
- Mercury (closest to the star).
- Venus (the hottest planet).
- Earth.
- Mars (the most accessible object for research).
They consist of metals, silicates, and their surface is hard. The outer group are the gas giants. These include:
- Jupiter.
- Saturn.
- Uranus.
- Neptune.
Their composition is characterized by a high content of hydrogen and helium. These are systems.
Satellites of the planets
When considering the question of how many satellites the Sun has, we should mention the celestial bodies revolving around the planets. IN Ancient Greece Venus, Mercury, Sun, Mars, Moon, Jupiter, Saturn were considered planets. It was only in the 16th century that Earth was included in this list. The sun has taken on its central significance in our system in the understanding of people. The Moon turned out to be a satellite of the Earth.
With the advent of more advanced technologies, it was found that almost all planets have their own satellites. Only Venus and Mercury do not have them. Today, about 60 satellites of planets are known, which are characterized by different sizes. The least famous of them is Leda. This one is only 10 km in diameter.
Most of these objects located in orbit gas giants, were discovered using automatic space technology. She provided scientists with photographs of such celestial objects.
Mercury and Venus
Our star has two rather small objects closest to it. The sun's satellite Mercury is the smallest planet in the system. Venus is slightly larger than him. But both of these planets do not have their own satellites.
Mercury has a highly rarefied helium atmosphere. It revolves around its star in 88 Earth days. But the duration of revolution around its axis for this planet is 58 days (by our standards). The temperature on the sunny side reaches +400 degrees. At night, temperatures down to -200 degrees are recorded here.
Venus's atmosphere consists of hydrogen with admixtures of nitrogen and oxygen. There is a greenhouse effect here. Therefore, the surface heats up to a record +480 degrees. This is more than on Mercury. This planet is best seen from Earth, as its orbit is closest to us.
Earth
Our planet is the largest among all representatives terrestrial group. It is unique in many ways. Earth has the largest celestial body orbiting among the first 4 planets from a star. The satellite of the Sun, which is our planet, differs significantly from all others in its atmosphere. Thanks to this, life became possible on it.
About 71% of the surface is water. The remaining 29% is land. The basis of the atmosphere is nitrogen. It also includes oxygen, carbon dioxide, argon and water vapor.
The Earth's satellite, the Moon, has no atmosphere. There is no wind, sounds, or weather. It is a rocky, bare surface covered with craters. On Earth, traces of meteorite impacts are smoothed out under the influence of life activity various types, thanks to the wind and weather. There is nothing on the moon. Therefore, all traces of her past are reflected very clearly.
Mars
It is the final planet of the terrestrial group. It is called the “Red Planet” due to the high content of iron oxide in the soil. This is a fairly Earth-like satellite. It revolves around the Sun for 678 Earth days. Scientists believed that life could once exist here. However, studies have not confirmed this. The satellites of Mars are Phobos and Deimos. They are smaller in size than the Moon.
It's colder here than on our planet. At the equator the temperature reaches 0 degrees. At the poles it drops to -150 degrees. This world is already available for astronaut flights. Spaceship can reach the planet in 4 years.
In ancient times, rivers flowed across the surface of the planet. There was water here. Nowadays there are ice caps at the poles. Only they consist not of water, but of carbon dioxide atmosphere. Scientists theorize that water may be frozen in large clumps beneath the planet's surface.
Gas giants
Behind Mars are the largest objects that accompany the Sun. The planets (satellites of the planets of this group) were studied using various techniques. The largest object in our system is Jupiter. It is 2.5 times more massive than all the planets orbiting the Sun combined. It consists of helium, hydrogen (which is similar to our star). The planet radiates heat. However, to be considered a star, Jupiter needs to become 80 times heavier. Has 63 satellites.
Saturn is slightly smaller than Jupiter. He is famous for his rings. These are ice particles of various diameters. The planet's density is less than that of water. Has 62 satellites.
Uranus and Neptune are located even further than the previous two planets. They were discovered using a telescope. They contain a large number of high-temperature modifications of ice. These are the Ice Giants. Uranus has 23 moons, and Neptune has 13.
Pluto
The sun's satellites are also complemented by a small object called Pluto. From 1930 to 2006 it held the title of planet. However, after lengthy discussions, scientists came to the conclusion that this is not a planet. Pluto falls into a different category. From the point of view of the current planetary classification, this is a prototype. The surface of the object is covered with frozen ice made of methane and nitrogen. Pluto has 1 satellite.
Having studied the main satellites of the Sun, it should be said that this is a whole system consisting of large quantity various objects. Their characteristics and indicators are different. All these objects are united by a force that forces them to invariably rotate around their central star.