Did the earth have a second satellite? How many artificial satellites revolve around the earth. The story of the "birth" of the moon

>>> How many satellites does the Earth have

Earth and its satellites: the number of objects near the third planet of the solar system. Find out more about the Moon and hypothetical natural satellites of the Earth with a photo.

Let's look into the night sky and count the number of earthly satellites. How many satellites does the Earth have you see? Come on, you haven't even tried it, because you know that there is only the Moon next to us. But this is strange, because Jupiter is able to boast a family of 67 members. Why are we worse?

Does the Earth have only one satellite

It turns out that there is only one satellite in the Earth's orbit? Well, officially it is. More precisely, 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 proved by the strange landscape on the far side of the moon, which could have been hit by another satellite.

Satellites 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, the largest moon of Neptune, Triton, rotates in the other direction and does not match the rest. It is believed that the planet pulled him towards itself by gravity from the Kuiper belt.

You may not know, but our planet already caught the asteroid 2006 RH120 in its nets in 2006-2007, before it escaped again. Or we have satellites that we simply cannot see because of their position, distance from Earth, and small size. Millimeter-sized asteroids can be located in Earth's orbit.

Are there still satellites of the Earth

How many satellites revolve around the Earth? Several notable celestial bodies live not far from us. Asteroid 3753 Cruithney is in orbital resonance with the third planet from the Sun. Its route is eccentric, but it takes a year to fly around the star. He was noticed in 1986 and after that a number of other objects were celebrated.

2007 TK7 is a Trojan asteroid that orbits 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 we will have them in the future. In the meantime, let's enjoy the bright neighbor.

We conducted an experiment: we asked our friends if they knew how many satellites the Earth has. Out of ten people, only one decided to clarify: “Which ones? Natural or artificial? " The rest remembered that the Earth has a satellite, the Moon, and they heard about some more. To dispel doubts in this matter, the Wonderful World decided to tell what satellites the Earth has and how they differ.

What is a satellite

A satellite is an object that orbits another object in space along a specific trajectory. Depending on the origin, satellites are natural and artificial.

The moon is a natural satellite of the Earth

There are 2 most common theories about how natural satellites appear.

The moon is the only natural satellite of the earth. Now this fact is generally accepted, but in the 19th and the first half of the 20th centuries, astronomers constantly assumed the presence of the Earth and other satellites.

Hypothetical natural satellites of the Earth

Quasi-satellites

What to see interesting about space

There are many materials about space now that you can simply admire, even if you do not understand anything in this area. If you like space, then the Wonderful World recommends watching:

Google Moon. You can examine the surface of the Moon and find where the expeditions landed: https://www.google.com/intl/ru/moon/

Gallery of Nasa. Especially cool photo of the day section: https://www.nasa.gov/multimedia/imagegallery/iotd.html

Instagram Nas. Here they publish short videos with the launch of rockets, stunning photos and videos from space: https://www.instagram.com/nasa/

Instagram Roscosmos. There are also photos and videos from space, especially many beautiful photos of the Earth: https://www.instagram.com/roscosmosofficial/

Roscosmos TV studio. News, popular science programs and videos in Russian: http://www.tvroscosmos.ru/

P.S. The article is popular science and is intended for beginners. Therefore, we wrote it in simple language, leaving out complex terminology.

Wishing you memorable moonlit nights,

Anastasia Gorbunova.

This article was written for the Wonderful World.

It is now generally accepted that the only natural companion The Earth is the Moon, however, assumptions about the existence of other satellites have been repeatedly put forward by astronomers, published in popular publications and described in works of fiction.

There are several near-Earth objects that are sometimes referred to as "second moons" or "second satellites." First, these are asteroids whose orbits are in resonance with the Earth's orbit. For example, quasi-satellites such as Cruithney move in orbital resonance with the Earth but revolve around the Sun, or Earth's Trojan asteroids such as 2010 TK7 move in the same orbit as Earth, but in front of or after it. In addition, it is possible for the Earth to capture temporary satellites, the orbit of which is unstable. Asteroid 2006 RH 120 is an example of such a satellite.

But it is much more interesting to see how battles on the scientific front regarding our issue have occurred in the past.

Valtemat's satellites

In 1898, Dr. Georg Walthemat, a scientist in Hamburg, reported that he had discovered a system of small satellites orbiting the Earth.

One of the satellites described by Valtematom was at a distance of 1,030,000 km from the Earth, had a diameter of 700 km and orbited the Earth in 119 days. It was also indicated that the satellite does not reflect enough light to be visible to the naked eye, but at certain points in time it is still visible. Valtemat made several predictions about the possible moments of observation of the satellite. Referring to observations made in 1881 in Greenland, he pointed out that "sometimes it shines like the sun in the night, but only for an hour or so." Valtematus believed that his companion had previously been observed by Giovanni Cassini and Jacques Maraldi, who mistook it for a sunspot. In addition, he referred to observations of the satellite of Venus at Saint Neot in 1761, believing that in this case, too, a second satellite of the Earth was observed. However, he did not provide arguments in favor of such an interpretation of these observations.

In February 1898, according to Valtemat's calculations, the satellite was supposed to pass along the disk of the Sun. On February 4, 1898, employees of the Greifswald post office, observing the sun with the naked eye, saw a dark object about 1/5 the diameter of the sun passing from 1:10 to 2:10 Berlin time. However, at the same time, the Sun was observed by astronomers W. Winkler and Ivo von Benko (Austria), who saw nothing but ordinary sunspots.

Failure did not diminish Valtemat's desire to search for a new satellite, and on July 20, 1898, he sent a message to Science magazine about the discovery of a third satellite, located at a distance of 427,250 km from Earth and having a diameter of 746 km. Waltemath called it "a truly turbulent and magnetic companion." The magazine commented on this message in this way: "Perhaps it is this satellite that leads the madness" (eng. "Perhaps it is also the moon presiding over lunacy" ).

Further searches

The possibility of the Earth having a second satellite was studied by William Pickering. To begin with, he calculated that a satellite orbiting at a distance of 320 km from the earth's surface, having a diameter of 30 cm and the same reflectivity as the Moon, should be visible in a 3-inch telescope, and a satellite with a diameter of 3 m would be visible to the naked eye. Pickering did not search for additional satellites of the Earth, although since 1888 he has been searching for a satellite of the Moon. Not finding such satellites, he concluded that if they exist, they must be less than 3 meters in diameter. Also in 1923, he published an article "A Meteorite Satellite" in Popular Astronomy, calling for amateur astronomers to look for small natural satellites.

Clyde Tombaugh (who discovered Pluto) was commissioned by the US Army to search for near-Earth asteroids. In March 1954, a press release was published explaining the need for such a study: it was indicated that such satellites could play the role of a kind of transfer stations for spaceships. Also, their detection was necessary in order to ensure that there were no false alarms from radars tracking spacecraft. In fact, it was the first systematic search for objects in near-Earth space. The search technique involved the use of a camera configured to track an object orbiting the Earth at a certain height. In the resulting images, the stars will appear as long lines, a satellite at a given altitude will be visible as a point, and one with a higher or lower orbit as a short line.

One of the "conspiracy theories" is associated with this search. According to ufologist Donald Kiho, who later became director National Research Committee on Aeronautical Phenomena, citing Pentagon sources, the search was undertaken to locate two orbiting Earth objects detected by long-range radar in mid-1953. Kiho stated in May 1954 that the search was successful and that one or both of the objects had been discovered and were of man-made nature. On August 23, 1954, the Aviation Week magazine published a report that two natural satellites were found at a distance of 400 and 600 kilometers from Earth. However, Tombaugh has publicly stated that no objects have been found. Popular Mechanics magazine reported in October 1955:

Professor Tombaugh has been silent on the research findings. He does not report whether any small natural satellites have been discovered. He, however, pointed out that the reports published in the press about the discovery of natural satellites at a distance of 400 and 600 kilometers from Earth 18 months ago do not correspond to reality. He also added that the research program had nothing to do with reports of sightings of so-called "flying saucers."

In 1959, Tombaugh presented a final conclusion, which said that the search did not produce any results: no objects brighter than 12-14 magnitudes were found.

Currently, an active search for objects in near-earth space is being carried out within the framework of several projects: Spaceguard, LINEAR, NEAT, LONEOS, a survey of Catalina, etc. These studies have not found any permanent satellites.

To be continued

The moon is the only natural satellite of the earth. We were once so sure of this that we didn't even give our moon a specific name. On the other hand, this is quite justified, since The moon is the brightest and largest object in the night sky, once again needs no introduction. The remaining 6 satellites of the Earth are so small and distant that they can only be seen through powerful telescopes. In addition, they revolve around the Sun, but are influenced by the Earth's gravity.

One can argue for a long time about whether such objects are natural satellites, but since, so to speak, the official point of view on this matter has not yet been determined, nothing prohibits attributing them to such. The International Astronomical Union, the leading organization in defining what this or that celestial body is and how this body is correctly called, promises in the near future to give a clear definition of the concepts of "satellite" and "component of the gravitational system." Therefore, while we have what we have.

So, together with the Moon, the Earth has 7 satellites. 5 of them are quasi-orbital asteroids or simply quasi-satellites, one more belongs to the class of Trojan asteroids. Up to a certain point, both of them (in this case, the other) were quite ordinary asteroids and rotated in their more or less stable orbits around the Sun, until one day they ran into a huge, relative to their size, Earth, as a result of which they fell into an orbital resonance 1: 1 with the last one. In other words, the revolution of the Earth and the "captured" asteroids was synchronized and now they make one revolution around the Sun in the same time.

Otherwise, these two types are fundamentally different from each other, so we will consider each separately.

Quasi-satellites of the Earth

What is a quasi-satellite? In principle, almost any celestial body that falls into a 1 to 1 orbital resonance with a planet can become it. Despite completely coinciding orbital periods, quasi-satellites always have a more significant eccentricity (the degree of deviation from the circle) of the orbit, and sometimes also a pronounced inclination relative to the plane of the ecliptic (the plane in which the planet rotates).

The main feature of quasi-satellites, as well as Trojan asteroids, is that at any given time they are exactly at the same distance from the Earth as a year ago. Actually, for this reason, they are ranked among natural satellites.

On the other hand, their "loyalty" to the planet is not always stable: the duration of the gravitational tandem can range from several orbital periods to hundreds of thousands of orbits.

Cruithney

The largest and most famous among the quasi-orbital satellites of the Earth - an asteroid Cruithney (3753)... It was discovered back in 1986 by an amateur astronomer and became the first known celestial body in the solar system to move in such a strange but stable orbit. Later, astronomers discovered similar companions from Venus, Jupiter, Saturn, Uranus, Neptune and even Pluto.

Unfortunately, we don't really know what Cruithney is. It is an asteroid about 5 km in diameter. It rotates in an orbit that is very elongated and inclined to the plane of the ecliptic, the perihelion (orbital point closest to the Sun) of which lies between the orbits of Mercury and Venus, aphelion - between Mars and Jupiter.

Satellites and planets of the solar system

Natural satellites of planets play a colossal role in the life of these space objects. Moreover, even we humans are able to feel on our own skin the influence of the only natural satellite of our planet - the Moon.

Natural satellites of the planets of the solar system have aroused keen interest among astronomers for a long time. To this day, scientists are studying them. What are these space objects?

Natural satellites of planets are cosmic bodies of natural origin that revolve around planets. The most interesting for us are natural satellites of the planets of the solar system, since they are in close proximity to us.

In the solar system, only two planets do not have natural satellites. These are Venus and Mercury. Although it is assumed that earlier Mercury had natural satellites, however, this planet lost them in the course of its evolution. As for the rest of the planets of 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 space 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 talk about below.

Satellite classification

Scientists divide planetary satellites into two types: artificial and natural satellites. Artificial satellites, or, as they are also called, artificial satellites are spacecraft created by people that allow you to observe the planet around which they orbit, as well as other astronomical objects from space. Usually artificial satellites are used to observe the weather, radio transmission, changes in the relief of the planet's surface, as well as for military purposes.

ISS is the largest artificial Earth satellite

It should be noted that not only Earth has satellites of artificial origin, as many people believe. More than a dozen artificial satellites created by mankind revolve around the two planets closest to us - Venus and Mars. They allow you to observe climatic conditions, changing the relief, as well as receive other relevant information regarding our space neighbors.

Ganymede is the largest satellite 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 in the solar system are asteroids that have been captured by the gravitational forces of the planets in 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 permanent companion. There is also a theory that the natural satellites of the planets are fragments of these planets themselves, which for one reason or another broke away from the planet itself during its formation. By the way, according to this theory, this is how the natural satellite of the Earth, the Moon, arose. This theory is confirmed by a chemical analysis of the composition of the moon. He showed that the chemical composition of the satellite practically does not differ from chemical composition of our planet, where the same chemical compounds 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.

Astronomers are keenly interested in the natural satellite. Most of the natural satellites of the planets in the solar system are composed primarily of ice, rock, or both, with the result that they lack an atmosphere. However, Titan has this, and it is quite dense, as well as lakes of liquid hydrocarbons.

Another natural satellite that gives scientists hope for the detection of extraterrestrial life forms is the satellite of Jupiter -. It is believed that under the thick layer of ice that covers the satellite, there is an ocean, inside which thermal springs operate - exactly the same as on Earth. Since some deep sea life on Earth exists from 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 on the planet of the solar system on which astrophysicists first discovered active volcanoes. It is for this reason that it is of particular interest to space explorers.

Research of natural satellites

Studies of natural satellites of the planets of the solar system have 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 foot on the main, closest to us, satellite of the Earth - the Moon. On July 21, 1969, American astronaut Neil Armstrong together with the crew of the Apollo 11 spacecraft stepped onto the lunar surface for the first time, which caused jubilation in the hearts of the then mankind and is still considered one of the most important and significant events in space exploration.

In addition to the Moon, scientists are actively involved in the study of other natural satellites of the planets of the solar system. For 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 the Earth images of several of Jupiter's largest satellites:,. In particular, thanks to these images, scientists were able to record the presence of volcanoes on the satellite of Io, and the ocean on Europa.

Today, the world community of space explorers continues to actively study 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 now developing a tourist lunar rover, on which many who wish could take a walk on the moon.