Satellites and planets of the solar system
The natural satellites of planets play a huge role in the life of these space objects. Moreover, even we humans are capable of feeling the influence of our planet’s only natural satellite – the Moon.
The natural satellites of the planets of the solar system have aroused keen interest among astronomers since ancient times. To this day, scientists are studying them. What are these space objects?
Natural satellites of planets are cosmic bodies of natural origin that orbit around planets. The most interesting for us are the natural satellites of the planets of the solar system, since they are in close proximity to us.
There are only two planets in the solar system that do not have natural satellites. These are Venus and Mercury. Although it is assumed that Mercury previously had natural satellites, this planet lost them in the process of its evolution. As for the rest of the planets in the solar system, each of them has at least one natural satellite. The most famous of them is the Moon, which is our planet’s faithful cosmic companion. Mars has, Jupiter -, Saturn -, Uranus -, Neptune -. Among these satellites we can find both very unremarkable objects, consisting mainly of stone, and very interesting specimens that deserve special attention, and which we will discuss below.
Classification of satellites
Scientists divide planetary satellites into two types: satellites of artificial origin and natural ones. Satellites of artificial origin or, as they are also called, artificial satellites are spacecraft created by people that make it possible to observe the planet around which they orbit, as well as other astronomical objects from space. Typically, artificial satellites are used to monitor the weather, radio broadcasts, changes in the topography of the planet's surface, and also for military purposes.
The ISS is the largest artificial satellite of the Earth
It should be noted that not only the Earth has satellites of artificial origin, as many people believe. More than a dozen artificial satellites created by mankind revolve around the two closest planets to us - Venus and Mars. They allow you to monitor climate conditions, changes in terrain, and also receive other relevant information regarding our space neighbors.
Ganymede is the largest moon in the solar system
The second category of satellites - natural satellites of planets - is of great interest to us in this article. Natural satellites differ from artificial ones in that they were created not by man, but by nature itself. It is believed that most of the satellites of the solar system are asteroids that were captured by the gravitational forces of the planets of this system. Subsequently, the asteroids took on a spherical shape and, as a result, began to revolve around the planet that captured them as a constant companion. There is also a theory that says that the natural satellites of planets are fragments of these planets themselves, which for one reason or another broke away from the planet itself during the process of its formation. By the way, according to this theory, this is how the Earth’s natural satellite, the Moon, came into being. This theory confirms chemical analysis of the Moon's composition. He showed that the chemical composition of the satellite is practically no different from chemical composition our planet, where the same chemical compounds are present as on the Moon.
Interesting facts about the most interesting satellites
One of the most interesting natural satellites of the planets of the solar system is the natural satellite. Charon, in comparison with Pluto, is so huge that many astronomers call these two space objects nothing more than a double dwarf planet. The planet Pluto is only twice the size of its natural satellite.
The natural satellite is of keen interest to astronomers. Most of the natural satellites of the solar system's planets are composed primarily of ice, rock, or both, resulting in them lacking an atmosphere. However, Titan has this, and quite dense one, as well as lakes of liquid hydrocarbons.
Another natural satellite that gives scientists hope for discovering extraterrestrial life forms is Jupiter’s satellite. It is believed that under the thick layer of ice that covers the satellite there is an ocean, inside of which there are thermal springs - exactly the same as on Earth. Since some deep-sea life forms on Earth exist thanks to these sources, it is believed that similar life forms may exist on Titan.
The planet Jupiter has another interesting natural satellite -. Io is the only satellite of a planet in the solar system on which astrophysicists first discovered active volcanoes. It is for this reason that it is of particular interest to space researchers.
Natural satellite research
Research on the natural satellites of the planets of the Solar System has interested the minds of astronomers since ancient times. Since the invention of the first telescope, people have been actively studying these celestial objects. The breakthrough in the development of civilization made it possible not only to discover a colossal number of satellites of various planets of the solar system, but also to set man on the main satellite of the Earth closest to us - the Moon. July 21, 1969, American astronaut Neil Armstrong and his crew spaceship Apollo 11 first set foot on the surface of the Moon, which caused rejoicing in the hearts of humanity at that time and is still considered one of the most important and significant events in space exploration.
In addition to the Moon, scientists are actively studying other natural satellites of the planets of the solar system. To do this, astronomers use not only visual and radar observation methods, but also use modern spacecraft, as well as artificial satellites. For example, the “” spacecraft for the first time transmitted to Earth images of several of Jupiter’s largest satellites:,. In particular, it was thanks to these images that scientists were able to record the presence of volcanoes on the moon Io, and the ocean on Europa.
Today, the global community of space researchers continues to be actively engaged in the study of the natural satellites of the planets of the solar system. In addition to various government programs There are also private projects aimed at studying these space objects. In particular, the world-famous American company Google is currently developing a tourist lunar rover, on which many people could take a walk on the Moon.
Currently, the Earth has only one natural satellite - the Moon. But relatively recently - some 6-7 thousand years ago - two moons could be seen above our planet. This is evidenced not only by the myths and traditions of many peoples, but also by geological finds. Blocks of pure iron In the north of Argentina there is the area of Campo del Cielo (translated as “heavenly field”). This name is taken from an ancient Indian legend, which tells about mysterious metal blocks falling from the sky at this place.
Pieces of iron, according to old Spanish chronicles, were found here back in the 16th century. Conquistadors used them to make swords and spears. Particularly lucky was a certain Herman de Miraval, who in 1576, in a rather remote area, among swampy lowlands, came across a huge block of pure iron. The enterprising Spaniard visited her several times and beat off pieces from her for various needs. In 1783, the prefect of one of the provinces, Don Rubin de Celis, organized an expedition to this block and, having discovered it after a long search, estimated its mass at approximately 15 tons. A detailed description of the object has not been preserved, and no one has seen it since then, although attempts to find the block were made more than once. In 1803, a meteorite weighing about a ton was discovered in the vicinity of Campo del Cielo. Its largest fragment (635 kg) was delivered to Buenos Aires in 1813. It was later acquired by the Englishman Sir Woodbine Darish and donated to the British Museum. This block of cosmic iron still rests on a pedestal in front of the museum entrance. Part of its surface is specially polished to show the structure of the metal with the so-called “Widmanstätten figures”, indicating the extraterrestrial origin of the object.
Iron fragments weighing from a few kilograms to many tons are still found in Campo del Cielo and its surroundings. Most weighed a lot 33.4 tons. It was found in 1980 near the town of Gansedo. American meteorite researcher Robert Hug tried to buy it and take it to the United States, but the Argentine authorities opposed this. To date, this meteorite is considered the second largest among all those discovered on Earth - after the so-called Khoba meteorite, weighing about 60 tons. Unusual large number meteorites found in a relatively small area indicate that a “meteor shower” once fell in this place. Evidence of this, in addition to the finds of the iron objects themselves, is a large number of craters in the Campo del Cielo area. The largest of them is the Laguna Negra crater with a diameter of 115 meters and a depth of more than 5 meters.
A huge meteorite exploded in the atmosphere
In 1961, W. Cassidy, a professor at Columbia University (USA) and the world's largest expert on meteorites, became interested in the findings at Campo del Cielo. The expedition he organized discovered a large number of small metal meteorites - hexaderites, consisting of almost chemically pure iron (96% of it, the rest is nickel, cobalt and phosphorus). Study of other meteorites found in different times in this area, gives the same composition. According to the scientist, this proves that they are all fragments of a single celestial body. Cassidy also drew attention to a strange fact: usually, when a large meteorite explodes in the atmosphere, its fragments fall to the Earth, scattering in an ellipse with a maximum diameter of about 1600 meters. And at Campo del Cielo the length of this diameter is 17 kilometers!
The published preliminary findings from Cassidy's research sparked interest around the world. The scientist was joined by hundreds of volunteer assistants, and as a result, new fragments of meteorite iron were discovered even at a considerable distance from Campo del Cielo, right up to the Pacific coast.
Satellite "two"
But it turned out that the area of finds was even wider. A discovery in Australia has shed unexpected light on the story of the Campo del Cielo meteorite. Here back in 1937, 300 kilometers from the town of Hanbury. In an ancient crater with a diameter of 175 meters and a depth of about 8 meters, an iron meteorite weighing 82 kilograms and several fragments of lesser weight were found. In 1969, they conducted a study of their composition and found that all these fragments are almost identical to the iron meteorites from Campo del Cielo.
Craters in the Hanbury area have been known since the 20s of the last century. There are several dozen of them, the largest of which reaches 200 meters, but most are relatively small - from 9 to 18 meters. During excavations carried out here since the 30s, over 800 fragments of meteorite iron were found in the craters, including four parts of one piece with a total mass of about 200 kilograms.
The final conclusion that Cassidy came to was this: a huge meteorite fell to Earth, but not suddenly. For some time before its fall, this celestial body revolved around the Earth in an elliptical orbit, gradually approaching the planet. Being in orbit could last quite a long time - a thousand years or more. However, under the influence of gravity, this second Moon eventually came so close to the Earth that it crossed the so-called Roche limit, after which it entered the atmosphere and broke up into fragments of different sizes, which fell to the surface of the planet.
The approximate date of the disaster was determined by radiocarbon dating - it turned out to be about 5800 years ago. Thus, the catastrophe occurred already within the memory of mankind, in the 4th millennium BC. e., when ancient civilizations began to emerge, leaving behind written monuments. In them we find mythologized references to the second natural satellite of the planet and the catastrophe caused by its fall. For example, the Sumerian clay tablets describe the goddess Innana crossing the sky and emitting a frightening radiance. An echo of the same events is, apparently, the ancient Greek myth of Phaeton.
The luminous celestial body is mentioned in Babylonian, Egyptian, Old Scandinavian sources, and the myths of the peoples of Oceania. The English ethnologist J. Fraser notes that of the 130 Indian tribes of Central and South America, there is not a single one whose myths do not reflect this theme.
“There is nothing surprising in all this,” writes American astronomer M. Papper, “after all, metal meteorites are very clearly visible in flight. Reflecting sunlight, they sparkle much brighter than stone meteorites; As for the large fireball made of pure iron, its luminosity in the night sky should have been brighter than the luminosity of the Moon.”
The elliptical orbit along which the bolide moved implied that at certain periods this object would pass close to the Earth. At the same time, the fireball came into contact with the upper layers of the atmosphere and became so hot that its shine should have been visible even in daylight. As the object approached our planet, its luminosity increased, causing the population panic horror. According to M. Papper, the orbit, which forced the fireball to either heat up upon contact with the earth's atmosphere, or, moving away from it, to freeze again in the icy cold of space, led to its destruction into pieces. Judging by the fairly large area over which the fragments were scattered - from South America to Australia - the fireball broke up in orbit and entered the Earth's atmosphere in the form of a string of separate fragments. The fireball could have caused the Great Flood
The largest pieces, according to experts, fell into the Pacific Ocean, causing waves of unprecedented size that could go around the Earth. The legends of the Indians of the Amazon basin say that stars fell from the heavens, there was a terrible roar and roar and everything was plunged into darkness, and then a downpour fell on the earth, which flooded the whole world. “The water rose to a great height,” says one of the Brazilian legends, “and the whole earth was immersed in water. The darkness and rain did not stop. People fled, not knowing where to hide; climbed the tallest trees and mountains.” The Brazilian legend is echoed by the fifth book of the Mayan codex, Chilam Balam: “The stars fell from the sky, crossed out the sky with a trail of fire, the earth was covered with ash, rumbled, trembled and cracked, shaken by tremors. The world was collapsing."
All these legends speak of a catastrophe accompanied by earthquakes, volcanic eruptions and floods. Its epicenter was clearly in the Southern Hemisphere, since the character of the myths changes as one moves north. Legends tell only about a strong flood. It was this event, apparently, that was preserved in the memory of the Sumerians and Babylonians and found its most vivid embodiment in the famous biblical myth of the Flood.
| 10. Satellites of minor planets >>9. Earth satellites
IN lately The question of how many satellites the Earth has is being discussed. Our neighbor the Moon is the only natural satellite of our planet. There are a huge number of artificial satellites of the Earth. However, in early 2002, an object was discovered in a chaotic orbit around the Earth. Calculations showed that it was captured from a heliocentric orbit. Passing near the Lagrange point L1 of the Sun-Earth system, it switched to a geocentric orbit, made 6 revolutions around the Earth and went back to the heliocentric trajectory. For almost a year and a half it was a satellite of the Earth. However, according to the laws of celestial mechanics, such capture can only be temporary; some dissipative forces are needed to make the trajectory satellite-like. Astronomers were faced with the question of how long the object had been in a heliocentric orbit. The timing of this object's entry into heliocentric orbit led astronomers to the conclusion that it was part of the Saturn rocket used during the launch of Apollo 12, launched into orbit to the Moon in 1969, that is, the object turned out to be of artificial origin. In 30 years, such a seizure could happen again.
In 2002, an asteroid was discovered, which was called a companion of the Earth. It moves in a so-called yoke-shaped orbit relative to the stationary Earth. Such a movement was discovered in 1911 by Brown, and a companion of the Earth was already known, called (3753) “Cruinha” with a size of 3-6 km. It moves either approaching the Earth or moving away, but avoiding a collision with our planet, being in a 1:1 resonance with the Earth. The period of revolution around the Sun is approximately one year, the same as that of the Earth.
Yoke orbits are named for their shape in a relative coordinate system that rotates with the accompanying planet. Both Trojan and yoke orbits are resonant in a 1:1 ratio to the accompanying planet, however, the yoke orbit also covers libration point L3, as well as points L4 and L5.
Although the Cruinha asteroid has a semi-major axis close to the Earth’s, other characteristics of the orbit are very different from the Earth’s orbit and therefore it is difficult to call it co-orbital, that is, moving in the same orbit as the Earth. Its orbit has a significant eccentricity and inclination to the ecliptic plane. In addition, the orbit of this asteroid intersects the orbits of Venus and Mars.
The same clamp-like behavior is shown by asteroid 2002 AA29. However, unlike Cruigny, it is co-orbital with the Earth, that is, its orbit is close to the Earth's. In January 2003, it came to its closest distance to Earth, equal to 12 distances from the Moon. Then it will begin to outpace the Earth in its movement around the Sun and will approach the Earth from the other side of the orbit in 2098. Every 95 years it approaches the Earth. An interesting feature of its movement is that after about 600 years it will move to another orbit and become a quasi-satellite of the Earth. Now the Earth has one satellite, but for about 50 years this small asteroid will move near the Earth as its satellite. In reality, both the Earth and the asteroid move around the Sun in a 1:1 resonance, that is, they orbit the Sun in one year. The existence of such orbits close to the earth’s is very important for the purposes of astronautics. When approaching the Earth, a spacecraft can be sent to the asteroid, which will bring us interesting information about small bodies and about the region of outer space closest to us.
> > > How many satellites does the Earth have?
Earth and its satellites: number of objects near the third planet of the solar system. Learn more about the Moon and hypothetical natural satellites of the Earth with photos.
Let's look at the night sky and count the number of earth's satellites. How many satellites does the Earth have you see? Come on, you didn’t even try, because you know that next to us there is only the Moon. But this is strange, because Jupiter can boast a family of 67 members. Why are we worse?
Does the Earth only have one satellite?
It turns out that there is only one satellite in Earth's orbit? Well, officially it is. More precisely, it is at the moment we have a single satellite. But millions or billions of years ago, there is a chance that there were other neighbors nearby. This is also proven by the strange landscape on the far side of the Moon, which could have received impacts from another satellite.
Companions are not immortal. For example, Mars has two, but this will not always be the case. Phobos is gradually approaching and one day it will simply crash into the planet. This should happen in 10 million years.
Perhaps in the future we will add to the earthly list. For example, Neptune's largest moon Triton rotates in the wrong direction and does not correspond to the others. It is believed that the planet pulled it towards itself with gravity from the Kuiper belt.
You may not know, but our planet already caught asteroid 2006 RH120 in its net in 2006-2007, until it broke out again. Or we have satellites that we simply cannot see due to their position, distance from Earth and small size. Millimeter-sized asteroids may be located in Earth's orbit.
Are there any other satellites on Earth?
How many satellites orbit the Earth? Several remarkable celestial bodies live not far from us. Asteroid 3753 Cruithney is in orbital resonance with the third planet from the Sun. His route is eccentric, but he spends a year orbiting the star. It was noticed in 1986 and after that a number of other objects were noted.
2007 TK7 is a Trojan asteroid that rotates in a stable position with us.
So, you know how many satellites the Earth has. The planet has a single Moon, but this is only now. We could have other satellites or will have them in the future. In the meantime, let's enjoy our bright neighbor.
Humanity has only just learned that the Earth has another satellite besides the Moon.
The second satellite of the Earth, astronomers say, differs from the big Moon in that it completes a full revolution around the Earth in 789 years. Its orbit is shaped like a horseshoe, and is located at a distance comparable to the distance from Earth to Mars. The satellite cannot approach our planet closer than 30 million kilometers, which is 30 times further than the distance to the Moon.
Relative motion of the Earth and Cruithne in their orbits.
Scientists say that the Earth's second natural satellite is the near-Earth asteroid Cruithney. Its peculiarity is that it intersects the orbits of three planets: Earth, Mars and Venus.
The diameter of the second Moon is only five kilometers, and this natural satellite of our planet will come to its closest distance to Earth in two thousand years. At the same time, scientists do not expect a collision between the Earth and Cruithne, which has approached our planet.
The satellite will pass from the planet at a distance of 406,385 kilometers. At this moment, the Moon will be located in the constellation Leo. Our planet's satellite will be fully visible, but the size of the Moon will be 13 percent smaller than at the time of its closest approach to the Earth. A collision is not predicted: the Earth's orbit does not intersect anywhere with Cruithney's orbit, since the latter is in a different orbital plane and is inclined to the Earth's orbit at an angle of 19.8 °.
Also, according to experts, in 7899 years our second moon will pass very close to Venus and there is a possibility that Venus will attract it to itself and thereby we will lose “Cruithney”.
The new moon Cruithney was discovered on October 10, 1986 by British amateur astronomer Duncan Waldron. Duncan spotted it in a photograph from the Schmidt telescope. From 1994 to 2015, the maximum annual approach of this asteroid to the Earth occurs in November.
Due to the very large eccentricity, the orbital speed this asteroid changes much more strongly than that of the Earth, so from the point of view of an observer on Earth, if we take the Earth as a reference system and consider it stationary, it turns out that not the asteroid, but its orbit rotates around the Sun, while the asteroid itself begins to describe ahead of the Earth a horseshoe-shaped trajectory, reminiscent of a “bean” in shape, with a period equal to the period of revolution of the asteroid around the Sun - 364 days.
Cruithne will approach Earth again in June 2292. The asteroid will make a series of annual approaches to the Earth at a distance of 12.5 million km, as a result of which there will be a gravitational exchange of orbital energy between the Earth and the asteroid, which will lead to a change in the orbit of the asteroid and Cruitney will again begin to migrate from the Earth, but this time in the other direction , - it will lag behind the Earth.
