The Moon is not the only satellite of our planet. The Earth Had Two Moons Theory of Big Men and Two Moons
In early August 2011, an article appeared in Nature, the authors of which suggested that the Earth had two moons in the distant past, that is, approximately 4.6 billion years ago. According to modern ideas, the earth's satellite was formed as a result of the collision of the Earth with the planet Theia, approximately the size of Mars. This planet knocked out a significant piece of the earth's crust, which, however, remained in orbit, froze and turned into the Moon. This theory, like any other, has several drawbacks, one of which is the uneven structure of our natural satellite.
To be precise, the side facing the Earth has, with the exception of craters, a relatively flat topography dominated by lava plains. The reverse side is radically different - it is covered with mountains and valleys, and the crust of the satellite on its reverse side is 50 kilometers thicker and contains more potassium, phosphorus and rare elements. Scientists have several options to explain these dramatic differences. According to one, for example, it’s all about the Earth’s tidal forces, which, during a tricky change in the orbit of the Earth’s satellite, caused the formation of mountains (pdf). According to another, meteorites are to blame for everything.
So, the hypothesis about the second Moon made it possible to solve the issue with the relief in a relatively natural way: at the first stage, two moons were formed, one of which then crashed into the other. She did this at a relatively low speed, so scientists jokingly nicknamed their hypothesis the “big slap.” Be that as it may, in the distant past the Earth probably had two Moons.
The new work submitted to Icarus is, of course, about something else (pdf), but they are united by the idea that the planet has another satellite. In their article, scientists from France, Finland and the United States, speaking globally, studied the dynamics of small bodies (asteroids) in the Earth-Moon system. To be a little more specific, scientists tried to answer several questions regarding those bodies that have been under the influence of the Earth’s gravity for quite a long time (that is, in fact, they turn out to be its satellites).
The reason for this interest was a discovery made in 2009. The fact is that in 2006, as part of the Catalina Sky Survey, an asteroid was registered, which was named 2006 RH120. It turned out that this object is a satellite of the Earth. Analysis of the reflected radiation led scientists to believe that the satellite was of man-made origin - also indicated by an orbit that was almost identical to that of J002E3, which is believed to represent the third stage of the Saturn that carried Apollo 12 into space. However, the 2006 RH120 could not be identified.
The object remained in orbit around the Earth from July 2006 to July 2007, after which, probably in search of adventure, it went into outer space, and in 2009, a paper appeared in Astronomy and Astrophysics, which convincingly proved that for a whole year astronomers observed a unique the object is the first registered temporary satellite of the Earth. This fact was all the more surprising because issues related to the capture of temporary satellites, for example by gas giants, have been studied relatively well, while the dynamics of such objects in the Earth-Moon system are generally unknown. It was all the more interesting for scientists to discover such an object.
As part of the new work, the researchers looked for answers to various natural questions regarding temporary satellites. For example, what is the average stable population of asteroids orbiting Earth? How long do they stay in orbit and, finally, how much of these celestial bodies falls to the Moon or to the Earth?
They did this in the now standard way - using a computer. The fact is that most of the equations that describe the motion of several (more than two, to be precise) bodies under the influence of gravity are not integrated, but they need to be studied somehow. This is where computers (along with numerical methods and statistics) come to the aid of scientists.
In its most general form, the methodology of such work looks like this: first, researchers create a completely deterministic (modulo the errors in the calculations introduced by the machine itself) model of the system being studied. Then, "test" particles are randomly generated with some initial conditions. The model is run several times, observing the behavior of the particles. After this, the collected data is analyzed statistically and some conclusions are drawn. In a certain sense, computers in this scheme make it possible to automate the process of formulating hypotheses, which, however, can later be refuted.
The model that was studied in the new work is the behavior of small bodies in the vicinity of the Earth-Moon system, and the test particles are asteroids. In total, scientists ran the model for 9,346,396,100 test asteroids. Of these, 18,096 fell into temporary orbits around the Earth. At the same time, the average time spent in Earth orbit was 286 days. Finally, of the more than 18 thousand objects remaining in orbit, only 169 fell to Earth.
Statistics built using this model allow scientists to make an interesting statement: at any given time there is at least one such satellite in Earth’s orbit. Although its diameter is likely only a few meters, it can be detected by existing telescopes.
The main thing, however, is not even that the hypothesis proposed by scientists can be verified. Such temporary satellites are excellent candidates for sending spacecraft to them - reaching an earthly satellite is much easier than chasing some asteroid throughout the solar system, as modern missions do. Scientists themselves say that with further improvement of the near-Earth space monitoring system, “catching” such objects will become much easier. All that remains is to wait until people can send another mission to the moon. True, temporary and second.
Moon observation night starts from October 12 to 13. Journalists from RIA Novosti invited scientists to tell what would happen if the Earth had a different satellite, to imagine that the Moon was really made of gold, glass or cheese. Experts from the "Science News" department of the economic Internet portal "Stock Leader" with details.
The cheese moon would shine brighter than the “normal” one, and if Titan itself were a satellite of the Earth’s surface, then enormous prospects would be open for astronauts and even for Gazprom - they couldn’t get rich like that, even if the Moon was made of gold, we’re sure specialists.
Observations of the Moon should take place from October 12 to 13. The moon will be quite low on the southwestern side, so in a clear sky it will be better visible, as long as the horizons are not obscured by buildings. Amateur astronomers can use not only a professional telescope, but also simple binoculars, although most likely it will not be possible to make a discovery with its help - but the sea, the largest craters will be visible, reports RIA Novosti.
The media write that observing the earth’s satellite evoked different associations among people. Writers and poets, for example, called the Moon “glass” or “golden” - the first epithet is found in Mikhail Bulgakov, Andrei Bely, Marina Tsvetaeva, the second - in Victor Kim and Yuri Annenkov. It was also similar to more mundane things - for example, cheese: there is even a comic theory that the satellite was created from just this product.
Opportunities for lunar exploration will appear in the near future
The moon is still not a very beautiful body - waterless, lifeless, without an atmosphere. Flights there were still a matter of prestige, states a senior researcher at the State Astronomical Institute. Sternberg Moscow State University named Vladimir Surdin. The expert named several “candidates” for the place of the Earth’s satellite. Among them, Europa, orbiting Jupiter, is not very different in size from the Moon, but outwardly completely different - it is covered with a serious “crust” of ice. In this regard, there is a boundless amount of water there, at least in the form of ice. And under the ice, as scientists suggest, there is an ocean hidden, the depth of which can reach 100 kilometers. There is very little water on the Moon, but it is extremely important for any expedition. After all, you can not only drink it, says Surdin, but also supply equipment with it and obtain fuel for rockets from it. Such a satellite would be much easier to develop than the Moon. The main obstacle in expeditions to the satellite is that you need to take everything with you, and since you don’t need water, it would be much easier, the expert sums up.
The second "candidate" for satellites is Titan, which orbits near Saturn. It has an atmosphere where there is no oxygen at all, but the pressure there is almost the same as on the surface of the Earth. If on the Moon the main obstacle to the activities of astronauts is vacuum, a heavy spacesuit is needed in order to move, then on Titan, Surdin is sure, this problem would be resolved.
In addition, there are lakes of liquefied gas - methane and other hydrocarbons. There they are liquid, since it is cold, but if Titan approaches the Sun, “putting” it in the place of the Moon, it would certainly become much warmer there. Huge lakes of liquid gas could evaporate, Titan's atmosphere would be completely saturated with them - by and large, a very good deposit would emerge. Even Gazprom would be interested in this, Surdin is sure.
Sputnik - tourism center
If Titan were an earthly satellite, it would become very interesting not only for experts, but also for ordinary people. Development could well follow the path of “tourism,” which would be relatively cheap on a cosmic scale—it would cost approximately 100 million US dollars, the expert estimates. People go to Everest with oxygen tanks - about the same as it would be possible to walk on Titan. Also, people now fly into orbit at their own expense, and with a little more money, they could also go to Titan, which orbits not far from Earth, Surdin thinks.
New satellite - new life forms?
Another Moon, in addition to other advantages, could very likely serve as a subject for study by exobiologists who are looking for other life forms. For example, the ocean, which is hidden under the icy European dome, is salty, potentially there could be some organisms there - but it is quite difficult to verify this now: it is expensive and long to fly to the satellite of Jupiter. It’s a different matter, notes Surdin, if only Europa were in the place of the Moon - after just three flights: people would have sent scientific expeditions to it long ago.
Legends say that some five to six thousand years ago two moons could be seen in the night sky above the Earth. This was the case until that very catastrophe happened, which is told in the legends and myths of many peoples of the world: “The stars fell from the sky, crossing out the sky with a trail of fire, the earth rumbled, trembled and cracked, shaken by tremors. The world was collapsing."
The consequences of this disaster were a shift of the earth's axis by 30 degrees, tectonic shifts and, possibly, the flooding of large areas of land.
But why and how did all this happen? Perhaps the answer to this question lies in Argentina.
The area of Campo del Cielo - "Field of Heaven" - is located in the north of the country. This name is reminiscent of an ancient Indian legend, which tells how a mysterious fireball once fell from the sky at this very place. Old chronicles claim that the Spanish conquistadors found a huge piece of iron at Campo del Cielo, which was used to make swords and spears.
In 1576, the Spaniard Erman Mexico de Miraval, among the swampy lowlands of the Gran Chaco, five hundred miles north of Santa Fe, came across a large block of iron. After this, the enterprising Spaniard visited the block four more times for iron and beat off small fragments from it for various needs.
The fifth and last expedition to the iron block was organized by Don Rubin de Celis in 1783. He estimated the mass of the iron fragment at 15 tons. True, for some reason no one else saw him, although attempts were made to find him repeatedly.
In 1803, a meteorite weighing about a ton was discovered in the vicinity of Campo del Cielo. Its largest fragment, weighing 635 kilograms, 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 so that one can see the structure of the metal with the so-called “Widmanstätten figures”, indicating the extraterrestrial origin of the object.
The unusually large number of meteorites found in a relatively small area indicates that several thousand years ago a “meteor shower” rained over the Earth, leaving many craters in the Campo del Cielo area.
The “Meteor Field” has the shape of an ellipse, elongated 17 kilometers along and 6 kilometers across. The largest crater is Laguna Negra; it has a diameter of 115 meters and a depth of more than two meters.
El Chaco (37 tons) is the largest fragment of the Campo del Cielo iron meteorite. It was found using a metal detector in 1969 at a depth of 5 meters.
One way or another, in 1961, an American scientist from Columbia University, W. Cassidy, became interested in the legends and finds of Campo del Cielo. The expedition he undertook discovered a large number of small metal meteorites, so-called hexaderites, consisting of almost chemically pure iron.
At the same time, the scientist 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 diameter is 17,000 meters! That is, an order of magnitude more...
The published preliminary findings of Cassidy's research caused a sensation. Hundreds of volunteer helpers came to him. As a result of their searches, new fragments of meteorite iron were discovered even at a distance of 75 kilometers from the “Heavenly Field”.
The final conclusion that the Cassidy expedition came to was this: a huge meteorite did not fall to Earth from near-solar orbit, as is usually the case. Before the fall, this celestial body revolved in an elliptical near-Earth orbit, gradually approaching the Earth. That is, to put it differently, this body was the second satellite of our planet!
According to this hypothesis, Luna 2 gradually moved closer to the Earth under the influence of gravity until it crossed the so-called “Roche limit” and fell apart. These fragments circulated in low-Earth orbit for some time, and then entered the atmosphere and began to fall to the surface of the Earth.
When did this cosmic catastrophe occur? A charred tree stump is discovered - the result of a giant fire caused by a meteorite bombardment. It was used to determine when the catastrophe happened - about 5800 years ago.
But was Luna 2 really a natural celestial body? Some ufologists believe that it was a huge spaceship from which an alien expedition landed on the island of Atlantis. And when it turned out that the members of the expedition had contracted some kind of infection such as HIV, which had penetrated aboard the starship, they had to destroy everything in one fell swoop - both the ship and the base on the island...
Like a kamikaze, the starship pilots wanted to send their ship straight to Atlantis. But something went wrong, the ship fell apart while still in the atmosphere, and some of its debris fell not only onto Atlantis, but also scattered across the Earth, ending up, in particular, on the territory of Argentina.
Which of the listed versions is correct, or are they all nothing more than misconceptions? All this remains to be clarified by future researchers. In the meantime, there is an active trade in large and small fragments of the Campo del Cielo meteorite all over the world. Look on the Internet. There are offers at very reasonable prices...
Wisdom says that "wherever each of us is, we will always see the same Moon..."
Eternal satellite of the Earth
Our planet is one of the wonders of the Universe, which humanity, despite great minds and the latest technologies, has not yet studied. Perhaps we have not learned even half of the secrets that the Earth keeps. And one of the questions that has worried our researchers for centuries is: “How many natural satellites does the Earth have?”
At first glance, this question has a one-word answer: we were taught from childhood that the Moon is a natural satellite of the Earth. But is this really so? Could there be other satellites near the planet that are still unknown to us?
The moon has long been the subject of man's worship, fear and wonder. Today we can confidently say what the Moon looks like and what substances make up the main composition of its surface. However, it still remains a mystery, which, perhaps, humanity will one day unravel, because the natural satellite of planet Earth continues to be studied.
Numerous moons
In fact, the Moon is far from the only one in the Universe. Each of the planets in our solar system has a certain number of its natural satellites. The Earth can boast of only one “partner”, but Jupiter has as many as 63 of them! The largest of them is called Ganymede.
Pluto's satellite, which was named Charon, is so large compared to the planet itself that astronauts initially mistook this “pair” for a double planet.
The smallest moon found in the Solar System is Dactyl. This baby, just a mile in diameter, is the satellite not of a planet, but of an asteroid. But previously scientists were sure that only planets could have a satellite! Dactyl successfully disproved this theory.
The story of the "birth" of the Moon
According to scientists, the Earth billions of years ago collided with another planet called Theia. For reference: in mythology, Thea is the mother of the moon goddess Selene. As a result of a powerful collision, two planets merged into one, and the fragments that broke off from the celestial body soon formed into a satellite. This explained a lot, but as recently as 2016, scientists disproved this theory. The thing is that the heavy isotopes of potassium found on the Moon could only appear as a result of exposure to incredibly high temperatures. A collision that caused such an effect would lead to the evaporation of a large part of the Earth.
This is interesting! Samples of our Moon indicate that it was once covered with active volcanoes.
In Blavatsky's book The Secret Doctrine there is a theory that the Moon is older than the Earth. It was she who gave her energy and strength to our planet, and she herself turned into its lifeless shadow. This theory is based on the chronology of the Hindus.
In 2017, virtual ufologist George Graham published a new theory about the purpose of the Earth’s natural satellite: they say that the celestial body is hollow inside and is inhabited by aliens. Graham's theory is based on photographs of the satellite's surface taken by NASA's orbital station, which contain images of artificial objects of regular shape.
Another Moon of the Earth
Today, researchers are confident that billions of years ago our Earth had two moons. As you know, the Moon is considered a body formed from the collision of the Earth with Theia. This theory explained the differences between its sides. So, one side, constantly visible to us, has a smooth surface formed by solidified lava, and the second, on the contrary, is covered with multiple mountains. In addition, its bark is much thicker, and its composition is dominated by rare elements.
Today, scientists have decided to expand the hypothesis, suggesting that the Earth was once accompanied by two satellites at once, the collision of which shifted lava flows to the hemisphere visible to us. Of course, this is just a theory, but almost the entire scientific history of our world is a theory.
"Capture" of planets
In 2006, observers discovered an object orbiting the Earth, which, after verification, turned out to be a natural cosmic body. Despite its modest size (only a few meters in diameter), the asteroid qualified as a full-fledged satellite. But before 2007, it left Earth’s orbit.
Experts explain that these temporary satellites are a normal phenomenon. Small asteroids are regularly discovered near the Earth, which disappear from orbit after time. The reasons for such visits are the gravitational force of the Earth and the Moon. Attracted to each other, they capture other cosmic bodies. As it turns out, our planet is always accompanied by some kind of temporary satellite.
Mysterious Lilith
Each of us knows the name of the Earth's natural satellite. Natural and unique. But at the end of the 19th century, astrologer Georg Waltemath from Hamburg announced that he had discovered a whole system of small satellites of the Earth. One of them, according to Valtemata, reached 700 km in diameter and was rarely visible to the naked eye.
In the winter of the same year, postal workers in Germany actually saw a dark object that passed across the Sun. But experts, who at the same time observed the night sky from another part of Germany and Austria, said that they saw nothing on the Sun except spots.
However, in 1918, Walter Hornold rediscovered Valtemata's moon, calling it Lilith. He believed that the masses of the Moon and Lilith were equal, but the latter was very difficult to detect in the sky. But today scientists consider his assumptions to be incorrect, since another satellite with a similar mass would cause a certain reaction from the Moon.
It is noteworthy that in astrology there is such a thing as a black moon. It is used when calculating the horoscope by astrologers and refers to esoteric symbols.
Other Earth satellites
Scientists have been trying for hundreds of years to find out whether the Earth has natural satellites that are invisible to the naked eye, but their orbits are in resonance with our planet (resonance is the vibration of two bodies in unison). Multiple studies have confirmed that our Moon is not the only natural satellite that is located near the Earth.
Despite the fact that only the Moon is a full-fledged natural satellite of the Earth, astronomers often notice other cosmic bodies in the orbit of our planet - the temporary satellites described above. But there are several so-called quasi-satellites.
What are quasi-satellites? This term refers to space objects that are in resonance with the orbit of a planet, which allows them to stay close to it for a long time.
Today, together with the Moon, the Earth has as many as eight satellites. Six of them are considered quasi-satellites, and another belongs to the class of Trojan asteroids. Initially, they revolved around the Sun, but then were attracted by the Earth and are now in a 1:1 resonance with it. As a result, asteroids, together with our planet, make a simultaneous circle around the Sun.
The peculiarity of quasi-satellites is their degree of deviation from their appearance and inclination relative to the plane of the planet. In addition, they are always at the same distance from the Earth. True, their “loyalty” is unstable, and over time they can break the gravitational tandem, which sometimes lasts hundreds of years.
Cruithney Quasi-satellite
The largest quasi-satellite belonging to the rare spectral class Q, discovered in 1986. Cruithney reaches a diameter of 5 kilometers and has a very strange orbital shape. When observing it from Earth, it appears to be moving in a horseshoe shape. At the same time, Krutney crosses the orbits of not only our planet, but also Venus and Mars.
Every year in November, Cruithney comes very close to the Earth, 30 times the distance to the Moon. You can see it with the naked eye - it resembles a dim star. Astronomers have not yet figured out the nature of Cruithne.
Duende - space baby
The quasi-satellite Duende (the name given to creatures from Spanish folklore that resemble a type of elf or dwarf) is the Earth's smallest satellite. It was opened in 2012. Despite its small size (about 30 meters in diameter), Duende comes as close as possible to the Earth. There is an opinion that its approach in 2013 and the flight of the fireball over the Earth are somehow connected, but this opinion has not been confirmed.
Attention! In 2016, another satellite was discovered near the Earth, the diameter of which does not exceed hundreds of meters. It will accompany our planet for several more centuries, and then move away from it. The trajectory of its movement resembles the jump of a frog, as the researchers say.
Conclusion
Other temporary satellites of the Earth do not have names - only numbers. These are satellites that were recently discovered and will be present near our planet for some time. Nobody knows exactly how much.
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.
