The central star of our system, in different orbits around which all the planets pass, is called the Sun. Its age is about 5 billion years. This is a yellow dwarf, so the size of the star is small. It doesn't run out very quickly. The solar system has reached approximately the middle of its life cycle. After 5 billion years, the balance of gravitational forces will be disturbed, the star will increase in size, gradually heat up. converts all of the sun's hydrogen into helium. By this time, the size of the star will be three times larger. Ultimately, the star will cool down, decrease. Today the Sun is made up almost entirely of hydrogen (90%) and some helium (10%).
Today, the satellites of the Sun are 8 planets, around which other celestial bodies, several dozen comets, as well as a huge number of asteroids revolve. All these objects move in their orbit. If you add up the mass of all the satellites of the Sun, it turns out that they are 1000 times lighter than their star. The main celestial bodies of the system deserve detailed consideration.
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 the processes of compression under the influence of gravity. There is only one star in our system - the Sun. 8 planets revolve 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 stars). They can reflect it. Also, the planet does not have other large celestial bodies near its orbit.
A satellite is also called an object that revolves around other, larger stars or planets. It is kept in orbit by the force of gravity 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.
Until recently, it was believed that our system has 9 planets. After much discussion, Pluto was removed from this list. But it is also part of our system.
The 8 major planets are held in their orbits by the Sun. A satellite (planet) can also have celestial bodies revolving around it. There are quite 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:
They consist of metals, silicates, their surface is hard. The outer group are the gas giants. These include:
Their composition is characterized by a high content of hydrogen and helium. These are systems.
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. Only in the 16th century the Earth was included in this list. The sun has taken in the understanding of people its central importance in our system. 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 the planets are known, which are characterized by different sizes. The least known of them is Leda. This one is only 10 km in diameter.
Most of these objects, located in the orbit of gas giants, were discovered using automatic space technology. She provided scientists with photographs of such celestial objects.
Our star has two rather small objects closest to itself. 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 satellites.
Mercury has a highly rarefied helium atmosphere. It orbits its star in 88 Earth days. But the duration of a revolution around its axis for this planet is 58 days (by our standards). The temperature on the sunny side reaches +400 degrees. At night, cooling down to -200 degrees is recorded here.
At Venus, the atmosphere consists of hydrogen with impurities 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.
Our planet is the largest among all representatives of the terrestrial group. It is unique in many ways. Earth has the largest celestial body in its orbit among the first 4 planets from a star. The satellite of the Sun, which is our planet, differs significantly from all in its atmosphere. Thanks to this, life became possible on it.
About 71% of the surface is occupied by 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, weather on it. It is a rocky, bare surface covered with craters. On Earth, the traces of meteor impacts are smoothed out under the influence of the vital activity of various species, thanks to the wind and weather. There is nothing on the moon. Therefore, all traces of her past are reflected very clearly.
It is the closing planet of the terrestrial group. It is called the "Red Planet" due to the high content of iron oxide in the soil. It is quite similar to the Earth satellite. It revolves around the Sun for 678 Earth days. Scientists believed that life could once exist here. However, studies have not confirmed this. Mars' moons are Phobos and Deimos. They are smaller 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. The spacecraft can reach the planet in 4 years.
In ancient times, rivers flowed on the surface of the planet. There was water here. Now there are ice caps at the poles. Only they do not consist of water, but of atmospheric carbon dioxide. Scientists suggest that water may be frozen in large chunks below the surface of the planet.
Beyond 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. It has 63 satellites.
Saturn is slightly smaller than Jupiter. He is known for his rings. These are ice particles of various diameters. The density of the planet is less than that of water. It has 62 satellites.
Uranus and Neptune are even further away than the previous two planets. They were discovered with a telescope. They contain a large number of high-temperature modifications of ice. These are Ice Giants. Uranus has 23 moons and Neptune has 13.
The sun's moons are also complemented by a small object called Pluto. From 1930 to 2006, he held the title of the 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 from 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 a large number of different objects. Their characteristics and indicators are different. What unites all these objects is a force that makes them constantly rotate around their central star.
Natural satellites are relatively small cosmic bodies that revolve around larger "host" planets. In part, a whole science is devoted to them - planetology.
In the 70s, astronomers assumed that Mercury had several celestial bodies dependent on it, as they caught ultraviolet radiation around it. Later it turned out that the light belonged to a distant star.
Modern equipment makes it possible to study the planet closest to the Sun in more detail. Today, all planetary scientists unanimously repeat that it has no satellites.
Venus is called similar to the Earth, since they have the same 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 of the solar system are unique in that they are completely alone.
Astrologers believe that Venus could have previously observed such, but to date, not a single one has been found.
Our native Earth has many satellites, but only one natural one, which every person knows from infancy, is the Moon.
The size of the Moon exceeds a quarter of the diameter of the Earth and is 3475 km. It is the only celestial body with such large dimensions relative to the "owner".
Surprisingly, its mass is also small - 7.35 × 10²² kg, which indicates a low density. Multiple craters on the surface are visible from Earth even without any special devices.
Mars is a rather small planet, which is sometimes called red because of its scarlet hue. It is given by iron oxide, which is part of it. 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, sowing panic and horror. Based on observations, it is gradually moving away from Mars. Phobos, named after the god who brings fear and chaos, is the only satellite that is so close to the "owner" (at a distance of 6000 km).
The surfaces of Phobos and Deimos are abundantly covered with craters, dust and various loose rocks.
To date, the giant Jupiter has 67 satellites - more than any other planet. The largest of them are considered the achievement of Galileo Galilei, since they were discovered by him in 1610.
Among the celestial bodies orbiting Jupiter, it is worth noting:
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.
Found 62 satellites, of which 53 have names. Most of them are composed of ice and rock, with a reflective feature.
The largest space objects of Saturn:
At the moment, Uranus has 27 natural celestial bodies. They are named after characters from famous works written by Alexander Pope and William Shakespeare.
Names and list by quantity with description:
The planet, whose name is consonant with the name of the great god of the seas, was discovered in 1846. She was the first to be found through mathematical calculations, and not through observation. Gradually, new satellites were discovered in her, until 14 were counted.
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 also the only satellite that rotates around itself in the opposite direction to the rotation of the "master".
Almost all satellites of Neptune have craters on the surface, volcanoes - both fiery and ice. They spew mixtures of methane, dust, liquid nitrogen and other substances from their depths. Therefore, a person will not be able to be on them without special protection.
Satellites are cosmic bodies that are smaller in size than the "host" planets and orbit the latter. The question of the origin of satellites is still open and is one of the key questions in modern planetary science.
To date, 179 natural space objects are known, which are distributed as follows:
Technologies are improving every year, finding more celestial bodies. It is possible that new satellites will be discovered soon. We can only wait, constantly checking the news.
The largest moon in our solar system is Ganymede, a moon of the 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. Closes the top three Callisto - Ganymede's "neighbor", with whom they share one "owner". Its scale is 4800 km.
Planetologists at all times asked themselves the question "Why do we need satellites?" 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 mandatory for the planet. Even without their presence, life can be formed and maintained on it. This conclusion was made by American scientist Jack Lissauer from the NASA Science Space Center.
Continuation. . .
On March 13, 1781, English astronomer William Herschel discovered the seventh planet in the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet in 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 have been discovered using spacecraft. Most satellites are made up of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christian 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 the size of Earth's, and consisting mostly of 90% nitrogen, with a moderate amount of methane.
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 the mass of Pluto is almost 500 times less than the Earth's, even less than the mass of the Moon. The mass of Pluto is 1.2 times 1022 kg (0.22 Earth masses). The average distance of Pluto from the Sun is 39.44 AU. (5.9 by 10 to the 12th degree km), the 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. The composition of Pluto supposedly includes rock and ice; the planet has a thin atmosphere composed of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nyx.
In the late 20th and early 21st centuries, many objects were discovered in the outer solar system. It has become clear that Pluto is only one of the largest Kuiper belt objects known to date. Moreover, at least one of the objects of the belt - Eris - is a larger body than Pluto and 27% heavier than it. 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 the planet was developed, according to which planets are considered to be bodies revolving around a star (and not being a star themselves), having a hydrostatically balanced shape and "clearing" the area in the region of their orbit from other, smaller, objects. Dwarf planets will be considered objects that revolve around 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 solar system objects. All other objects revolving around the Sun and not being 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. Five dwarf planets are officially recognized by the International Astronomical Union: 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 plutoids celestial bodies that revolve 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 relation to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily assigning to plutoids all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1. If later it turns out that the object assigned to the plutoids is not a dwarf planet, it will be deprived of this status, although the assigned name will be left. 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 on the basis of 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 Earth orbit. The USA did it second, a year later. Later, many countries launched their satellites into Earth's orbit - however, satellites purchased in the same USSR, the USA or China were often used for this. Now satellites are launched even by radio amateurs. However, many satellites have important tasks: astronomical satellites explore the galaxy and space objects, biosatellites help to conduct scientific experiments on living organisms in space, meteorological satellites make it possible to predict the weather and observe the Earth’s climate, and the tasks of navigation and communication satellites are clear from their name. 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 5800 satellites have been launched since 1957, 3100 of them are still in space, but only about one thousand of these three thousand are working.
Artificial satellites of the moon (ASL)
At one time, ISLs helped a lot in the study of the Moon: when entering its orbit, the satellites photographed the lunar surface in high resolution and sent the images 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 the Soviet Union was again ahead of everyone: in 1966, the Soviet automatic station Luna-10 was the first to enter the 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 it is not so easy to switch to a heliocentric orbit: the device must gain the second space velocity without exceeding the third one. And approaching the planets, the device can slow down and become a satellite of the planet, or accelerate and completely leave the solar system. But now NASA satellites orbiting the Sun near the Earth's orbit began to perform detailed measurements of the parameters of the solar wind. The Japanese satellite observed the Sun in the X-ray range for about ten years - until 2001. Russia launched a solar satellite in 2009: Koronas-Photon will explore the most dynamic solar processes and monitor solar activity around the clock to predict geomagnetic disturbances.
Artificial satellites of Mars (IMS)
The first artificial satellites of Mars were ... three ISMs at once. Two space probes were released by the USSR ("Mars-2" and "Mars-3") and one more by the USA ("Mariner-9"). But the point is not that the launch took place "in a race" and there was such an overlay: each of these satellites had its own task. All three ISMs were launched into significantly different elliptical orbits and carried out different scientific studies, 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 solar wind flow around Mars, the ionosphere and atmosphere, relief, 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 (WIS)
The first WIS were once again Soviet spacecraft. Venera 9 and Venera 10 went into orbit in 1975. Reaching the planet. They were divided into satellites and landers. Thanks to the WIS radar, scientists were able to obtain radio images with a high degree of detail, and the devices that gently landed on the surface of Venus took the world's first photographs of the surface of another planet ... The third satellite was the American Pioneer-Venus-1 - it was launched three years later.
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Satellites of the planets of the solar system: the exact number for the planets of the inner and outer systems, the largest and smallest satellite, description, photo, research.
For many centuries, people could observe the only available satellite - the Moon. But in 1610, Galileo makes a breakthrough and finds 4 satellites of Jupiter, proving that other celestial bodies have moons. But how many of them are there in our system?
It is difficult to answer how many satellites the planets of the solar system have, because there are confirmed candidates. Now they can be counted up to 173, but if you take into account the dwarf planets, then 182. You can study in more detail each satellite for the solar planets in order in the tablet.
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| Group Himalaya |
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| Group Karma |
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The solar system is also home to 200 very tiny objects located in the Kuiper belt, and representatives of TNOs (trans-Neptunian objects). Approximately 150 orbit Saturn (62 with officially confirmed orbits). If we combine everything, we get the result of 545 moons.
internal system
The inner system is the zone with the first four planets from the Sun. But here we only consider our planet Earth and Mars, because Venus and Mercury rotate alone.
The Earth's Moon extends in a radius of 1737 km, and in terms of mass - 7.3477 x 10 22 kg. Density index - 3.3464 g / cm 3. It is believed that it was formed after the collision of the Earth with a large celestial body.
The Martian lunar family consists of Phobos and Deimos. Both are in a tidal block and resemble asteroids. It is believed that the planet pulled them from the asteroid belt. Phobos is located closer (9377 km) and extends for 27 km.
Deimos spans only 12.6 km and is 23,460 km distant, which means it takes 30.35 hours to orbit. In total, 3 satellites live in the internal system.
External system
Beyond the asteroid belt, the outer solar system begins and the lunar quantity increases sharply. And it all starts with the gas giant and the largest planet - Jupiter. He has the largest number - 79, which can grow to 200 if applicants are confirmed.
The four largest were named after the discoverer Galileo Galilei - Galilean: Io (the most volcanic), Europa (with an underground ocean), Ganymede (the largest in the system) and Callisto (an underground ocean and an ancient surface).
There is also the Almateya group with four satellites less than 200 km in diameter. Irregular satellites are very tiny and distant over long distances. They are also divided into families according to composition and orbital path.
Saturn may have 150 moons, but 62 are considered official (53 have names). 34 of them have a diameter of less than 10, and 14 - from 10 to 50 km. But there are also large-scale specimens stretching for 5000 km. All of them got their names in honor of the titans.
The interiors are composed of water ice and have a rocky core, icy mantle, and crust. The outer ones go beyond the E-ring. Titan is considered the largest with a diameter of 5150 km and a mass of 1350 x 10 20 kg. It contains 96% of the mass of the entire planetary orbit.
There are 27 moons revolving around Uranus. Among the largest are Miranda, Ariel (the brightest), Umbriel (the darkest), Oberon and Titania.
All of these moons are believed to have originated in the accretion disk of the planet. Each has an equal volume of rock and ice. Only Miranda is almost completely icy.
Neptune has 14 moons named after sea nymphs. The right ones are close to the planet, while the wrong ones formed from the remnants of early collisions and move far in retrograde orbits.
The largest is Triton with a diameter of 2700 km. It is distant at 354,759 km from the planet and has enough mass to achieve hydrostatic balance.
Dwarf planets and other objects
A detailed study of the system showed that the moons revolve not only around the planets. There are also dwarf, TNO and other bodies. Mostly seen near Pluto, Eris, Haumea and Makemake.
Pluto has 5 moons, among which Charon is the largest and closest.
There are also Nikta and Hydra found in 2005, Kerberus in 2011 and Styx in 2012. Among them all, only Nikta and Hydra have an elongated shape and could not become spherical. Some believe that Pluto and Charon should be taken as a binary system. They are located in the tidal block, and the satellite may have cryogeysers.
Hiiaka and Nakama, found in 2005, revolve around Haumea. The first extends for 310 km and may be part of a dwarf planet. The second makes an orbital passage in 18 days.
Eris has Dysnomnia, seen in 2005.
In 2016, S/2015 (136472) was discovered near Makemake, stretching for 175 km, and its distance is 21,000 km.
The largest and smallest satellites of the solar system
The king of all moons in the system is Ganymede with a diameter of 5262.4 km. And the smallest are S / 2003 J9 and S / 2003 J12, whose size is only 1 km.
Now you know how many satellites are in the solar system. Do not forget that we are talking only about those satellites that we managed to detect.
