In what order are the planets located from the sun? solar system

Relatively recently, about 20 years ago.

The latest discoveries were made in 2014, when the Kepler telescope team managed to discover 715 new planets. These planets revolve around 305 stars, and their orbital structure resembles the Solar System.

Most of these planets are smaller than the size of the planet Neptune.

A team of researchers led by Jack Lissauer analyzed stars that had more than one planet orbiting them. Each of the potential planets was spotted back in 2009-2011. It was during this time that 961 more planets were discovered. When checking the planets, a technique known as multiple checking was used.

New methods for checking planets

In the early years of scientists' search for planets outside the solar system, their status was revealed as a result of studying one planet after another.

Later, a technique appeared that made it possible to check several celestial bodies at the same time. This technique detects the presence of planets in systems where several planets orbit a single star.

Planets located outside the solar system are called exoplanets. When discovering exoplanets, there are strict rules for naming them. New names are obtained by adding a small letter to the name of the star around which the planet orbits. In this case, a certain order is observed. The name of the first planet discovered includes the name of the star and the letter b, and subsequent planets will be named similarly, but in alphabetical order.

For example, in the “55 Cancer” system, the first planet “55 Cancer b” was discovered in 1996. In 2002, 2 more planets were discovered, which were named “55 Cancer c” and “55 Cancer d”.

Discovery of the planets of the solar system

Such planets of the solar system as Mercury, Venus, Mars, Jupiter and Saturn were known in antiquity. The ancient Greeks called these celestial bodies “planets,” which meant “wandering.” These planets are visible in the sky with the naked eye.
Along with the invention of the telescope, Uranus, Neptune and Pluto were discovered.

Uranus was recognized as a planet in 1781 by the English astronomer William Herschel. Before that, he was considered a star. Neptune was calculated mathematically long before it was discovered using a telescope in 1846. German astronomer Johann Halle used mathematical calculations before he was able to discover Neptune using a telescope.

The names of the planets of the solar system come from the names of the gods of ancient myths. For example, Mercury is the Roman god of trade, Neptune is the god of the underwater kingdom, Venus is the goddess of love and beauty, Mars is the god of war, Uranus personified the sky.

The existence of Pluto became known to science in 1930. When Pluto was discovered, scientists began to believe that there were 9 planets in the solar system. In the late 90s of the 20th century, a lot of controversy arose in the world of science over whether Pluto is a planet. In 2006, it was decided to consider Pluto a dwarf planet, and this decision caused much controversy. It was then that the number of planets that orbit the Sun was officially reduced to eight.

But the question of how many planets there are in the solar system has not been fully resolved.

Sources:

• Solar System Planets: Order of the 8 (or 9) Planets, Robert Roy Britt, 2012
• NASA's Kepler Mission Announces a Planet Bonanza, 715 New Worlds, 2014

The question of the number of planets is not as clear-cut as it might seem at first glance. The answer to it is determined both by the meaning given to the word “planet” and by the level human knowledge about the Universe.

From the point of view of modern astronomy, a planet is a celestial body revolving around a star. Such a body is large enough to be rounded by its own gravity when formed, but not massive enough for thermonuclear fusion. The first criterion distinguishes a planet from asteroids, and the second from stars. But it wasn't always like this.

The word “planet” itself is translated from Greek language as "wandering". This is how in ancient times they called the luminaries, which, from the point of view of an earthly observer, move across the sky, in contrast to the “fixed” stars. Of course, in those days people knew only those planets that could be seen with the naked eye: Mercury, Venus, Mars, Jupiter, Saturn. They did not identify the earth with such bodies, because it was considered the “center of the universe,” which is why ancient astronomers spoke of five planets.

In the Middle Ages, the Sun and Moon were also considered as planets, so there were seven planets.

The revolution in astronomy carried out by N. Copernicus forced the Sun to be removed from the list of planets and the Earth to be included in it. We also had to reconsider the status of the Moon, which revolves not around the Sun, but around the Earth. Starting with the discovery of the satellites of Jupiter by G. Galileo, we can talk about a new concept: a body rotating not around a star, but around a planet - a satellite. Thus, at the beginning of modern times there are six planets: five that were known in ancient times, and the Earth.

Subsequently, new planets were discovered: in 1781 - Uranus, in 1846 - Neptune, in 1930 - Pluto. Since that time, it was believed that there were 9 planets in the solar system.

In 2006, the International Astronomical Union specified the concept of a planet. Along with the already mentioned criteria - revolution around the star, rounded shape - a third one was added: there should be no other bodies in orbit that are not satellites of this one. In light of recent discoveries, Pluto did not meet the latter criterion and was therefore excluded from the list of planets.

So, according to modern astronomers, there are 8 planets in the solar system.

Exoplanets

Since the time of Giordano Bruno, people have wondered whether there are planets in the universe orbiting other stars. Theoretically, this seemed possible, but there was no evidence.

The first evidence appeared in 1988: calculations made by a group of Canadian scientists suggested that the star Gamma Cephei has a planet. In 2002, the existence of this planet was confirmed.

This marked the beginning of the search for planets located outside the solar system - exoplanets. It is impossible to indicate the exact number of even those discovered by astronomers, because scientists regularly discover new planets, but the number of discovered exoplanets already exceeds a thousand.

The diversity of exoplanets is amazing. Among them there are also those that are not in the solar system: “hot Jupiters”, water giants, ocean planets, diamond planets. There are also those that are similar to Earth, but it is not yet possible to know whether there is life on them.

Astronomers estimate that the number of exoplanets in the Milky Way galaxy alone may exceed 100 billion. How many of them there can be in the entire infinite Universe is impossible to say even hypothetically.

Video on the topic

Sources:

• How many exoplanets are in our galaxy in 2017

Venus is the most mysterious planet in the solar system. It is no coincidence that she was named after the goddess of love and beauty from ancient Roman mythology. This is the only planet that bears the name of a goddess. All other planets are named after male gods.

Instructions

Ancient Greek astronomers mistook Venus for two completely different stars. The one they saw in the morning was called Phosphorus. The one who appeared in the evenings was called Hesperus. Later it was proven that this is the same celestial body. Venus is one of the brightest objects that can be seen from Earth. Only the Sun and Moon are brighter. You can see Venus so well not only because of its size. The distance from Earth to Venus is less than to other planets, and its atmosphere reflects the sun's rays very well.

Venus is often called Earth's twin sister. For a long time, until the 70s. In the 20th century, scientists assumed that the climate and topography of Venus were similar to the climate and topography of Earth. It was already known that the two planets are very close in a number of parameters. They have almost the same size, composition, mass, density and gravity. In 1761, the Russian scientist M.V. Lomonosov discovered the presence of an atmosphere on Venus. The only significant difference was that the Earth had a satellite, while Venus had no satellites. Through telescopes, only a dense curtain of clouds could be seen, preventing the surface of the planet from being seen. In their imagination, scientists imagined a planet covered with dense tropical forests, and seriously discussed the idea that Venus could become a second home for earthlings.

With the beginning of the space age, Venus became the most “visited” planet in the solar system. Since 1961, more than 20 spacecraft, probes and artificial satellites have been sent to explore Venus. All dreams of moving people to Venus dissipated after the first research vehicles burned up in its atmosphere. Only the tenth apparatus sent to study it was able to reach the surface of Venus; this happened in 1979. The surface temperature was measured at 500 degrees Celsius. It has been established that the atmosphere of Venus consists of 96% carbon dioxide, which is 400 thousand times more than the same figure on Earth.

In 1975, the first photographs of Venus were taken. The sky on Venus is bright orange. All surfaces are brown or orange, with a green tint in places. There is no water on the planet itself; water vapor is present in the atmosphere in negligible quantities, its content is 0.05%. The clouds on Venus are poisonous, consisting mainly of sulfuric acid. The planet's topography is predominantly flat. Two areas were discovered that protrude greatly above the main surface. The largest plateau, called the Ishtar Archipelago, is comparable in size to Australia. The highest point of Venus is Mount Maxwell, its height is 12 km. This is higher than Everest - itself high point Earth.

The entire surface of Venus is covered with craters. Craters were formed both due to falling meteorites and after volcanic eruptions. The planet looks like a hot desert, completely riddled with craters. According to the latest research, Venus has active volcanoes. Some scientists believe that the climate on Venus can be changed. To do this, you just need to start the process of photosynthesis on the planet. Scientists propose to drop algae capable of rapid reproduction on Venus. By releasing oxygen, they will reduce the carbon dioxide content in the atmosphere. The planet will begin to cool, and conditions will appear for the development of the biosphere.

Uranus, the seventh and third largest planet in the solar system, was discovered by British astronomer William Herschel in 1781. This is the first planet discovered using a telescope. Uranus is located 2,877,000,000 km from the Sun, which is 19 times the same distance from Earth. What else is interesting about the seventh planet of the solar system?

Azure Planet

Uranus is 4 times larger and 14.5 times heavier than Earth, and is 390 times less illuminated by the Sun. It belongs to a group of planets called gas giants. Moreover, it is one of two ice giants in nearby space. The main components of its atmosphere are hydrogen and helium; carbon, methane and other impurities are also present in some quantities. It is methane that gives the planet its azure-greenish color.

The clouds of the planet Uranus have a complex, layered structure. The top layer consists of methane, the main layer consists of frozen hydrogen sulfide. Below is a second cloud layer consisting of ammonium hydrogen sulfate. Even lower are clouds of water ice. It's difficult to determine where the atmosphere ends and the planet's surface begins, but Uranus' structure is still somewhat denser than that of other gas giants.

In the center of the planet there is a relatively small rocky core, and the mantle consists of icy modifications of methane, ammonia, helium, hydrogen and rocks. Metallic hydrogen, present in the depths of other giant planets, is absent on Uranus. Uranus has its own magnetic field, the origin of which is still unknown, and radiates much more heat into space than it receives from the Sun.

Uranus is the coldest planet in the solar system. The minimum temperature recorded here is 224°C. Powerful and long-lasting storms are observed in the planet’s atmosphere, with wind speeds reaching 900 km/h.

The movement of Uranus occurs in an almost circular orbit. The period of revolution around the Sun is 84 Earth years. Uranus has a unique feature - its rotation axis is only 8° away from the orbital plane. The planet seems to be rolling around the Sun, swaying from side to side. Another feature of Uranus is its retrograde or reverse daily rotation. So in the solar system, besides it, only Venus rotates. A day on Uranus is 17 hours and 14 minutes.

As a result of all of the above, an unusual change of seasons has been established on Uranus. The change of seasons at the poles and equator of the planet occurs differently. At the equator of Uranus there are 2 summers and 2 winters throughout the year. The duration of each period is almost 21 years. At the poles there is one winter and one summer lasting 42 Earth years. During the equinoxes, in a small zone close to the equatorial regions of the planet, the usual cycle of day and night occurs.

Ring system and moons of Uranus

Uranus has 13 thin dark rings - 9 main, 2 dust and 2 outer, formed, later inner. The first 11 are located at a distance of 40,000-50,000 km. The outer rings, discovered in 2005, are located approximately 2 times further than the main ones, and form a separate system. The thickness of the rings does not exceed 1 km. Incomplete arcs and dust streaks are observed between the main rings.
Width central ring reaches 100 km, it is the most significant in size. The rings of Uranus are opaque, and consist of a mixture of ice and some dark material. It is assumed that the age of the ring system does not exceed 600 million years. Perhaps it arose during the collision and destruction of the planet’s satellites orbiting around it or captured as a result of gravitational interaction.

The orbital planes of Uranus' 27 satellites practically coincide with the equatorial plane of the planet. None of them have an atmosphere and do not reach the size of small planets. The satellites of the inner group are fragments of irregular shape, measuring 50 - 150 km. They all circle Uranus within a few hours. The orbits of the inner satellites are changing rapidly. They are likely suppliers of material for the planet's rings.

The largest are the main satellites. There are 5 of them. The diameter of the largest of them - Titania - is 1158 km. The main moons are made of ice and rock. The third group - external satellites - have reverse rotation, small sizes, and orbits that have a significant angle of inclination to the plane of the planet's equator. The largest one, Ferdinind, makes one revolution around Uranus every 8 years. They are probably all captured by the planet's gravitational field from outer space.

Mercury is the smallest planet in the system, which is closest to the Sun. Mercury has no satellites.

The surface of the planet is covered with craters that appeared about 3.5 billion years ago as a result of massive bombardment by meteorites. The diameter of the craters can range from a few meters to more than 1000 km.

The atmosphere of Mercury is very thin, consists mainly of helium and is inflated by the solar wind. Since the planet is located very close to the Sun and does not have an atmosphere that would retain heat at night, the surface temperature ranges from -180 to +440 degrees Celsius.

By earthly standards, Mercury completes a full revolution around the Sun in 88 days. But a Mercury day is equal to 176 Earth days.

Venus is the second planet closest to the Sun in the solar system. Venus is only slightly smaller in size than Earth, which is why it is sometimes called “Earth’s sister.” Has no satellites.

The atmosphere consists of carbon dioxide with admixtures of nitrogen and oxygen. The air pressure on the planet is more than 90 atmospheres, which is 35 times more than on Earth.

Carbon dioxide and the resulting greenhouse effect, dense atmosphere, and proximity to the Sun allow Venus to bear the title of “hottest planet.” The temperature on its surface can reach 460°C.

Venus is one of the brightest objects in the earth's sky after the Sun and Moon.

Earth

Mars is the seventh largest planet in the solar system. "Red Planet", as it is also called due to the presence large quantity iron oxide in the soil. Mars has two satellites: Deimos and Phobos.
The atmosphere of Mars is very thin, and the distance to the Sun is almost one and a half times greater than that of the Earth. Therefore, the average annual temperature on the planet is -60°C, and temperature changes in some places reach 40 degrees during the day.

Distinctive features of the surface of Mars are impact craters and volcanoes, valleys and deserts, and polar ice caps similar to those on Earth. Mars has the most high mountain in the solar system: the extinct volcano Olympus, whose height is 27 km! And also the largest canyon: Valles Marineris, whose depth reaches 11 km and length - 4500 km.

Jupiter is the largest planet in the solar system. It is 318 times heavier than the Earth, and almost 2.5 times more massive than all the planets in our system combined. In its composition, Jupiter resembles the Sun - it consists mainly of helium and hydrogen - and emits a huge amount of heat equal to 4 * 1017 W. However, in order to become a star like the Sun, Jupiter must be 70-80 times heavier.

Jupiter has as many as 63 satellites, of which it makes sense to list only the largest - Callisto, Ganymede, Io and Europa. Ganymede is the largest moon in the solar system, even larger than Mercury.

Due to certain processes in the inner atmosphere of Jupiter, many vortex structures appear in its outer atmosphere, for example, stripes of clouds in brown-red shades, as well as the Great Red Spot, a giant storm known since the 17th century.

Saturn is the second largest planet in the solar system. Business card Saturn is, of course, its ring system, which consists mainly of icy particles different sizes(from tenths of a millimeter to several meters), as well as rocks and dust.

Saturn has 62 moons, the largest of which are Titan and Enceladus.
In its composition, Saturn resembles Jupiter, but in density it is inferior even to ordinary water.
The outer atmosphere of the planet appears calm and homogeneous, which is explained very dense layer fog. However, wind speeds in some places can reach 1800 km/h.

Uranus is the first planet discovered by telescope, and the only planet in the Solar System that orbits the Sun "lying on its side."
Uranus has 27 moons, which are named after Shakespearean heroes. The largest of them are Oberon, Titania and Umbriel.

The composition of the planet differs from gas giants in the presence of a large number of high-temperature modifications of ice. Therefore, along with Neptune, scientists have classified Uranus as an “ice giant.” And if Venus has the title of “hottest planet” in the solar system, then Uranus is the coldest planet with a minimum temperature of about -224°C.

Neptune

Astronomer from the city of Alexandria Claudius Ptolemy for the first time in the history of science, relying on the knowledge of his predecessors, he created a harmonious mathematical theory of the movement of visible bodies in the sky. Ptolemy placed the Earth at the center of the Universe, and therefore we call the ideas he developed geocentric system of the world. This was the first serious step in studying the solar system as a whole. Ptolemy's views enjoyed universal recognition for almost a millennium and a half.

In the 16th century Nicolaus Copernicus developed heliocentric system of the world, according to which the center of the Universe is not the Earth, but the Sun. This meant recognizing the fact that feelings can greatly let people down: the immobility of the Earth turns out to be apparent, but in fact it constantly revolves around the Sun at high speed.

One should not think that Ptolemy, who once placed the Earth at the center of the universe, was an unscrupulous and misguided ignorant, and Copernicus opened people's eyes to genuine scientific truth. For his time, Ptolemy achieved a huge scientific achievement: he created a great theory that mathematically strictly described the movements of all visible heavenly bodies. His theory came from practice and was tested by practice. It became a kind of standard for all subsequent natural science. Ptolemy, as the author of this theory, can rightly be considered one of the classics of natural science. In the person of Copernicus, science for the first time had to debunk the great theory. It turned out that scientific truths are not eternal strongholds: from time to time they need revision. Science from time to time rejects what previously seemed completely unshakable. And this is one of the important lessons of the development of science!

IN mid-19th century century a scientific discipline was born astrophysics. A century and a half of studying planets using astrophysics methods has led to many important discoveries. But a real revolution in knowledge about the bodies of the solar system occurred only after the beginning of the space age. Today we have learned immeasurably more about the cosmic environs of the Earth than we knew just some ten to fifteen years ago. The surface maps of Mercury, Venus, the Moon, and Mars from the “Atlas of Terrestrial Planets and Their Satellites” prepared by MIIGAiK were used as the basis for the section maps.

Planets of the Solar System

Celestial bodies too cold to emit their own light like stars, close in shape to a sphere and, as a rule, very small in mass and size in comparison with the mass and size of stars, have long been called PLANET. Many stars, by the force of their gravity, hold systems of several planets near them. We have the most information at our disposal about the planets revolving around the Sun, especially about the planet on which we live - the Earth. Together with the Sun, these planets form solar system.

The planets of the Solar System are visible from Earth due to the sunlight they reflect: bathed in the sun's rays, they look similar to the Earth's sky. stars sparkling with their own light. So far, 9 planets of the solar system, including Earth, are known. Modern titles These planets are given the names of Greek and Roman deities. Five of them were observed primitive people Since ancient times, three have been discovered using a telescope. The last planet to be discovered was Pluto in 1930. Astronomers do not lose hope of sooner or later finding more planets in the solar system, but their efforts have so far been fruitless.

Characteristics of the planets
(in order of distance from the Sun)

The average distance of the Earth from the Sun is 149,600 thousand km.
Time of one revolution - 365.256 days
Earth mass - 5.976 x 10 27 g
Average density - 5.52 g/cm 3

Evolution and origin of the solar system

The round dance of the planets of the Solar System is located near the plane passing through the solar equator and circles around the Sun in the same direction - from west to east. According to existing ideas, the Sun and planets were born together from a gas-dust cloud. The huge cloud was cold and had an irregular shape.

Under the influence of gravitational forces, the cloud should little by little twist and flatten. In its central part a clot of matter condensed - a future star named the Sun. The compacting central clot grew, took on the shape of a ball and eventually “flashed” - thermonuclear reactions began to heat it up, releasing huge amount light and warmth. Volatile substances near the Sun evaporated and were thrown into the densest and thickest - the middle part of the cloud. Particles of the cloud, circling around the flaming star-Sun, collided and interlocked. This is how the “embryos” of planets appeared. Small and denser planets grew close to the Sun. And in the middle part of the cloud, massive, loose planets swelled. All this happened about 5 billion years ago.

Terrestrial planets

Geologists drill tens of thousands of wells on the Earth's surface. The deepest wells on land were drilled in our country and reach 12 km. This is a huge value, but it is extremely small compared to the size of the Earth: after all, the diameter of the Earth is about 13 thousand kilometers. If we compare the Earth with the human body, then even the deepest wells are less deep than a mosquito bite on the human body. Therefore, data on the internal structure of the Earth have to be collected not from drilling results, but by completely different methods.

During earthquakes, vibrations from sources located deep in the body of the Earth are recorded by sensitive seismometers. From these data, one can get an idea of ​​the speed of propagation of vibrations in the body of the Earth, which change during the transition from one layer of matter to another. In this way, it was established that the interior of the Earth is divided into three layers. In the center of the planet, an iron-rich core. It is surrounded by the so-called mantle. And the thin outer layer of our planet, which can be likened to the skin of an apple, is called bark.

Space flights to other terrestrial planets brought information that the internal structure of all is similar to the internal structure of the Earth. The four planets close to the Sun - Mercury, Venus, Earth and Mars - have much in common. They are small in size and weight, their average densities are close to each other, exceeding the density of water by 4-5 times. They are similar in their chemical and mineralogical composition. They have few satellites - only one near Earth and two near Mars; Mercury and Venus have no satellites at all. Once upon a time, in the preplanetary cloud, even before the final formation of the planets, numerous “flakes” of matter of various sizes were circling, and the surfaces of planets close to the Sun, like wounds, bear countless traces of their impacts.

Astronomers identify the four planets listed below common name planets of the terrestrial group. Spacecraft have repeatedly photographed close to all the terrestrial planets and worked for a long time on the surface of Venus and Mars.

Therefore, the landscapes on the surface of all these four planets are not a figment of the artist’s imagination, but reflect completely reliable information about what will open to the gaze of the traveler when he lands on these planets. From top to bottom: fragments of the surfaces of Mercury, Venus, Earth and Mars, photographed from Space.

Mercury

Mercury rotates on its axis in the same direction as the Earth (counterclockwise when viewed from the north), and completes one revolution every 58.7 Earth days. This means that in 2 revolutions around the Sun, the planet rotates exactly 3 times around its axis. The period of a planet's axial rotation refers to the period of its revolution around the Sun strictly as 2: 3; such a connection of periods is called resonant.

On the spread in the upper left corner the sizes of the Earth and the planet closest to the Sun, bearing the name, are compared ancient god trade, merchants and profits of Mercury. Planet Mercury 2.5 times smaller than Earth in size and 20 times less in mass. One revolution around the Sun takes Mercury 88 Earth days. The planet is completely devoid of atmosphere. Due to its proximity to the Sun, its illuminated side is hot: at noon at Mercury's equator, the temperature rises 400 degrees above zero on the Celsius scale. True, at the opposite point at the same time it drops to almost 200 degrees below zero.

The terrestrial planets bear traces of impacts of blocks, stones and small grains of sand, which were preserved from the preplanetary cloud and, like projectiles, bombarded the formed cold celestial bodies from time to time. As a result of such impacts, overlapping round craters - craters - appeared on the surface of the planets. Mercury, not protected by an atmosphere, like the Moon, was subjected to particularly severe bombardment. Outwardly, it looks exactly like the Moon, densely pitted with countless crater “pockmarks.”

Venus

In the photo on the right, the narrow crescent of the planet Venus is taken from Earth using a telescope. Below is a space photograph of the cloud cover of Venus. The impenetrable clouds of Venus reliably covered its surface from the eyes of astronomers. Because of the reflection sunlight with its clouds, Venus looks like the brightest luminary in the earth’s sky, second only to the Sun and Moon; for her brilliance she received the name of the Roman goddess of love. A year on Venus lasts 225 Earth days, and it takes 243 Earth days to rotate around its axis, and it rotates in the direction opposite to the direction of Earth’s rotation.

The thickness of the atmosphere of Venus is many times greater than that of the Earth. It consists mainly of carbon dioxide. According to space experiments, it turned out that the huge atmosphere of Venus presses on its surface 90 times stronger than the earth’s atmosphere, and the temperature on the surface of Venus, due to the so-called greenhouse effect, reaches almost 500 degrees Celsius. The diagram on this page gives an idea of ​​the structure of the atmosphere of Venus and the location of the three tiers of Venusian clouds. Venus's clouds contain some chemically aggressive compounds, such as sulfuric acid.

The rotation of Venus has an amazing property. Let's imagine the moment when Venus and Earth are at the shortest distance from each other. Due to different speeds of revolution around the Sun, they disperse and meet again at the shortest distance from each other after 584 days. At this time, Venus will again be facing the Earth with the same hemisphere as at the previous meeting.

Earth

The planet on which we live has become an object of intense interest ever since people learned to think and reason. What does the Earth rest on? How is it structured? How to use for your benefit the wealth of the Earth's interior that surrounds us natural conditions? Today, several people are studying the Earth at once. scientific disciplines, mainly those whose names contain the Greek root geo - earth: geology, geochemistry, geophysics, geodesy, geomorphology and others. Together with the earth sciences, astronomy studies it as one of the members of the solar system in comparison with other planetary bodies.

Based on rock age measurements, we believe that the Earth condensed from a pre-planetary cloud about 4.5 billion years ago. It is important that independent estimates of the ages of those celestial bodies for which they are most reliable - the Sun and Moon - lead to the same values. This confirms modern ideas about the simultaneous origin of all bodies in the Solar System.

The Earth is truly the only body of its kind in the Solar System that has huge open bodies of water on its surface: oceans, seas, rivers, lakes. Most scientists are inclined to believe that the simplest organic life originated in the oceans of the Earth and, constantly becoming more complex, acquired all those numerous forms that we observe in the history of the Earth. In memory of their origin, all forms of living beings on Earth grow and multiply in accordance with the one genetic code. The diagram on the left clearly illustrates the answer. modern science to the question of how and in what time frame the evolution of life on our planet took place.

With the advent of the space age, scientists were given unprecedented means of studying the Earth. The very first launches of artificial Earth satellites made it possible to understand the picture of the interaction of the planet with the surrounding interplanetary environment. Photographs of the Earth from Space were of great importance for geologists and geophysicists. If previously it was necessary to collect measurement data step by step at scattered points, at stops on expedition routes, or to combine hundreds of individual aerial photographs, i.e. As if to paint a portrait of the planet bit by bit, now space photographs have made it possible to look at geological structures and their features over vast areas at once, and have made it possible to better understand the structure of the Earth as a single planetary body.

With the help of satellites, the so-called inner and outer radiation belts of the Earth were discovered. The Earth's radiation belts, filled with streams of charged particles, are an important component of the near-Earth space that we call Earth's magnetosphere.

After all, the Earth's magnetic field serves as a barrier to the flow of solar radiation, the so-called solar wind, flowing into it. On the sunlit side of the Earth, the magnetosphere extends to 10-15 Earth radii; from this side it is pressed towards the planet by the oncoming wave of solar wind. And on the opposite side, the magnetosphere is extended like the tail of a comet at a distance of up to several thousand Earth radii, forming an extended geomagnetic tail.

There is a point of view according to which about 200 million years ago all the continents formed a single supercontinent, behind which the name Pangea. More common among geologists is the view that initially there existed not one, but two supercontinents on the surface of the Earth - Gondwana in the Southern Hemisphere and Laurasia in the Northern Hemisphere.

The Mid-Atlantic Ridge is hidden under the waters of the Atlantic Ocean. The bends of the ridge basically follow the contours of the coasts of the Atlantic Ocean, which serves as another proof of its nature: Atlantic Ocean- a giant seam on the body of the planet. Here, rocks rising from the depths of the Earth pour out. The continents on opposite sides of the Mid-Atlantic Ridge are slowly moving away from each other.

Moon

The Moon is the only satellite of the Earth. Astronomers have long searched for other natural satellites near the Earth, even tiny ones. But specially organized “patrols” confirmed: there are no other natural satellites larger than 30 meters in the vicinity of the Earth. The Moon is small in comparison with its owner, the Earth; The diameter of the Moon is 4 times smaller than that of the Earth. The mass of the Moon is 81 times less than the mass of the Earth.

The period of revolution of the Moon around the Earth is exactly equal to the period of its rotation around its own axis - just like the guys who dance around the Christmas tree. If you look at them from the side, then during one round of the tree, each one turns around its axis exactly once. Due to the equality of the two periods, the Moon always faces the Earth with the same side of its surface.

The constant bombardment of the Moon by meteorites is the reason that the entire surface, several meters deep, is covered with a layer of crushed substance, which subsequently sinteres and forms a compacted spongy mass. This thin top layer of the lunar surface is called regolith. This is why the huge temperature fluctuations from day to night on the surface of the Moon (at the equator from +130 to -170°) die out at a depth of only a few tens of centimeters. Even at a depth of just one meter, the temperature on the Moon is constant.

Just like the surface of Mercury, the surface of the Moon is dotted with countless craters. The surface of the Moon is characterized by vast lowlands once filled with basaltic lava, which, according to a long tradition, are called lunar seas. There is a Sea of ​​Rain, a Sea of ​​Cold, a Sea of ​​Clarity, a Sea of ​​Vapor and others on the Moon. The largest lunar plain is called the Ocean of Storms. The mountains on the Moon are called the same as on Earth: Alps, Caucasus, Carpathians and others. Most craters are named after scientists.

Mars

Mars makes one circuit around the Sun every 687 Earth days. For an observer on Earth, it returns to its previous position in the sky relative to the Sun every 780 days. The planet Mars rotates around its axis in the same direction as the Earth, spending 24.6 Earth hours per rotation. For this reason, the length of day and night on Mars is very similar to what we know on Earth. Mars has an atmosphere that is incomparably more rarefied than the atmosphere of the Earth; the reddish surface of Mars shines through it, and since ancient times it has been known that this celestial body in the night sky is distinguished by a reddish tint. Hence the name of the planet: for its “bloody” shade it received the name of the ancient Roman god of war. By the way, in honor of the same god, the first month of the Roman calendar was named March.

The atmosphere of Mars partly protects it from meteorite bombardment, and dust storms erase traces of meteorite impacts from the surface much faster than what happens on the “windless” celestial bodies Mercury and the Moon.

The Earth's rotation axis is inclined to the plane of its movement around the Sun by 66.5°. The axis of Mars is inclined almost exactly the same - by 65°. As a result, on Mars, just like on Earth, there is a change of seasons: spring, summer, autumn and winter occur there. Seasonal changes in the external appearance of the surface of Mars were noticed by astronomers long ago based on observations from Earth.

According to data from the Mariner 9 spacecraft, it was discovered that after the rapid melting of the seasonal cap of solid carbon dioxide (dry ice), a constant cap of water ice remained throughout the summer. Currently, the diameter of the permanent cap in the northern hemisphere exceeds 1000 km, and in the southern hemisphere it is about 300 km.

Mars is richer than other terrestrial planets in terms of the number of satellites - there are two of them. Both opened in 1877 during the so-called great opposition of Mars, i.e. at the moment when Mars comes closest to Earth. Great confrontations always come at the end of summer or beginning of autumn, alternating one after another with an interval of either 15 or 17 years.

The satellites of Mars received names from Homer's Iliad: these are the companions of the god of war Phobos And Deimos- Fear and Horror. They are very small - the average diameter of Phobos is 22 km, and Deimos is 12 km. The distance of Phobos from the planet is less than 10 thousand km, as a result of which the period of its revolution around Mars (less than 8 Earth hours) is shorter than the period of daily rotation of Mars itself. Such a case is unique in the Solar System: although Phobos orbits near Mars in the same direction as the vast majority of other planetary satellites, for an observer on the surface of Mars, it will rise not in the east, but in the west. Deimos is 23.5 thousand km away from Mars. Its orbital period is just over 30 hours.

Space images have made it possible to create a detailed map of the Martian surface, reflecting a wide variety of terrain: long, broken valleys, canyons, craters, volcanoes, dune fields and much more. The main extinct Martian volcano is so large that it was indicated on maps as an independent feature of the surface back in the era of telescopic sketches.

The diameter of the foot of Mount Olympus is about 600 km, and the height reaches 24 km. Three more volcanoes: Mount Askrian, Mount Peacock and Mount Arsia reach a height of up to 27 km. For comparison, recall that largest volcano The land of Mauna Loa on the Hawaiian Islands in the Pacific Ocean has a foot diameter of just over 200 km and rises above the ocean floor by only 9 km.

Giant planets

In order of distance from the Sun, the first four places in the solar system are occupied by the terrestrial planets, and the fifth to eighth places are occupied by the planets of the Jupiter group or, as they are also called, giant planets. They are sharply different from the terrestrial planets in all respects. Firstly, they have gigantic sizes and enormous masses with small densities close to the density of water. Secondly, chemically they consist mainly of hydrogen and helium gases, characteristic of chemical composition Sun. Thirdly, each of the giant planets has many satellites and, finally, fourthly, they are all surrounded by thin rings.

At the center of these planets is believed to be a liquid core of silicates and metals: iron and nickel. The core is enclosed in a “shell” of solidified hydrogen and helium, and the hydrogen in the lower part of the “shell” must transform into a special, metallic state. Above is a hydrogen-helium atmosphere, but due to high pressures, the lower part of the atmosphere is highly dense and viscous. It looks more like an ocean than a shell of gas.

Jupiter

The diameter of Jupiter is 11 times greater than the diameter of the Earth. The average density of Jupiter is only 1.3 times higher than the density of water, and therefore its mass more mass Earth is only 318 times. This largest of the planets in the solar system bears the name of the most important Roman god of thunder.

Jupiter spends about 12 Earth years on one circle around the Sun, but the huge planet rotates around its axis, one might say like a top: it spends less than 10 Earth hours on one revolution.

If you “dive” to Jupiter from outer space, you will first pass through the usual rarefied atmosphere. Then you get into a cloud layer - a kind of fog with small solid particles. Below you will enter a layer of significant compaction, like slush, which will become thicker and thicker until it turns out to be essentially solid. There is no clearly defined boundary between the solid body of the planet and the gaseous shell on Jupiter.

Observed from Earth, of course, hard surface planets, and the upper layer of clouds. The interaction of the planet's magnetic field with the solar wind of the surrounding interplanetary medium results in the formation of Jupiter's magnetosphere, which is much larger and much more complex than Earth's magnetosphere. To simulate Jupiter's field, you have to imaginarily insert 2 or even 4 magnetized rods into the body of the planet.

A remarkable formation in the atmosphere of Jupiter is known as the Great Red Spot. It attracted attention in 1878, when it stretched for 50 thousand kilometers and struck astronomers as a huge brick-red region of the atmosphere. Analyzing old telescopic sketches of Jupiter, astronomers found a red spot in archival materials dating back to the 17th century. The red spot changes in size and partly shifts relative to the surface: it either drifts like an iceberg in the ocean, or sways like a buoy anchored with a long chain.

The Great Red Spot is most likely a persistent atmospheric vortex, but the spot's persistent red color has not yet been satisfactorily explained.

The total number of satellites of the planet known today is 16. The four largest were discovered immediately as soon as Galileo aimed his telescope at Jupiter. They are called Galilean satellites. 9 more satellites in different times were discovered by astronomers from Earth and 3 were discovered using space photography data. The satellites of Jupiter, starting with Leda, are small in size, have an irregular shape and revolve around Jupiter in highly elongated orbits with large inclination angles to the equator of the planet (up to 30°). The four outermost moons orbit Jupiter in the opposite direction. In space photographs, thin rings of Jupiter, indistinguishable from Earth, were discovered.

Moons of Jupiter:

• Metis
• Adrastea
• Amalthea
• Europe
• Ganymede
• Callisto
• Himalia
• Lysithea
• Elara
• Ananke
• Karma
• Pasiphae
• Sinope

Saturn

3 Over the course of three and a half centuries of helescopic observations, Saturn remained the only planet in the Solar System whose appearance was decorated with a unique landmark - the rings surrounding the planet. It was known that the average thickness of the rings is negligible - about 1 km, and the total width exceeds 60 thousand km. It was known that the rings are located strictly in the plane of the planet’s equator and consist of many fragments, stones, and dust particles. Only in the era of space flights was it proven that rings are characteristic of all 4 planets of the group of giant planets.

The structure of Saturn's rings, as captured in space photographs, turned out to be much more complex than could be imagined from observations from Earth. The planet is surrounded not by a few, but by many thousands of rings nested within one another. Quite unexpectedly, it turned out that there are bright and narrow rings.

The sixth planet of the solar system is named after the ancient Roman god of farmers and harvest. Saturn is the most distant of the planets known since ancient times. During the most favorable periods of its visibility, Saturn is observed in the earth's sky all night long, from evening to morning. It looks quite bright, but its brilliance is noticeably dimmer than that of Venus and Jupiter. Saturn makes one revolution around the Sun in almost 30 Earth years. It rotates around its axis as quickly as Jupiter.

From ground-based observations, 11 satellites of Saturn were known. But after receiving his space photograph, Saturn became a record holder. To date, the list of satellites of Saturn includes 17 names. The largest among them is Titan, as well as Jupiter's moon Ganymede, which is larger than the planet Mercury. The diameter of Titan is only 2.5 times smaller than the diameter of the Earth. The internal structure of Titan appears to be somewhat reminiscent of the structure of the Earth's body: the interior of Titan is stratified into a core, mantle and crust. The composition of Titan's solid body is ice with an admixture of silicate rocks.

• Atlas
• Prometheus
• Pandora
• Epimetheus
• Mimas
• Enceladus
• Tethys
• Telesto
• Calypso
• Diona
• Elena
• Titanium
• Hyperon

Uranus

The planet Uranus is sometimes seen with the naked eye at the limit of discrimination as a very faint bluish-greenish dot, but only under extremely favorable circumstances. It was not known to the ancient stargazers; it was discovered using a telescope by the great Andean astronomer William Herschel. The mass of Uranus is almost 7 times less than the mass of its neighbor Saturn. The planet spends 84 Earth years on one revolution around the Sun. The name Tsano is named after the Greek deity of the sky.

Uranus has serious distinctive feature. The planet's axis of rotation lies close to the plane of its revolution around the Sun, so we can say about Uranus that it is the only planet that revolves around the Sun "lying on its side."

Over two centuries of telescopic observations of Uranus, the five largest satellites of this planet and its rings were discovered. The modest satellites also gained fame as a result of a photographic survey of the outskirts of Uranus from a spacecraft flying near it. It is believed that the satellites of Uranus, like the satellites of Saturn, are predominantly icy. Their names have nothing to do with mythology. They recall a series of literary heroes. The names Oberon and Titania chosen by V. Herschel were borrowed from V. Shakespeare's comedy "A Midsummer Night's Dream". W. Lassel in 1851 used the name Ariel from Shakespeare's "The Tempest" and Umbriel from ALope's poem "The Stolen Lock". The tradition is continued in the newest ten names, so that the system of satellites of Uranus has become a kind of celestial “Shakespearean reserve”.

Miranda turned out to be the most unusual among the satellites of Uranus. According to the figurative expression of one of the space geologists, little Miranda presented to earthlings a collection of all kinds of geological structures that exist on the bodies of the Solar system.

Satellites:

• Cordelia
• Ophelia
• Bianca
• Cressida
• Desdemona
• Juliet
• Portion
• Rosalind
• Belinda
• Miranda
• Ariel
• Umbriel
• Titania
• Oberon

Neptune

Neptune has all the characteristic features of a giant planet. Its mass is 17 times the mass of the Earth with an average density of less than 1/3 of the Earth's. It takes 16 hours to complete one revolution around its axis. Neptune, like other giant planets, is surrounded by rings.

Thanks to advances in space technology and electronics, data on Neptune expanded significantly in 1989. In addition to the two previously known satellites - Triton and Nereid - 6 more new ones were spotted. The planet's rings have been discovered. It turned out that a dry “geyser” is constantly erupting on the surface of Triton, emanating from the depths of this celestial body a jet of solid particles to a height of 8 km.

• Naiad
• Thalassa
• Galatea
• Despina
• Larissa
• Proteus
• Triton
• Nereid

Pluto-Charon system

Pluto was discovered as a result of a long search in 1930. The planet spends 250 Earth years on one full revolution around the Sun. On average, Pluto is farther from the Sun than Neptune, but Pluto's orbit is so elongated that at times this planet ends up inside Neptune's orbit. Such a change in places occurred, in particular, in the period from 1979 to 1999. Pluto is now the only planet that has not been visited by automatic spacecraft.

In 1978, a satellite of Pluto was accidentally discovered from ground-based observations, which was named Charon. Charon is estimated to be located side by side with Pluto. It is only 2 times smaller in size than the planet itself and revolves around it as if connected to Pluto by a rod: the period of revolution of the satellite around Pluto coincides with the period of rotation of Pluto around its axis. The satellite therefore never rises or sets relative to the horizon at any point on the surface of this planet. It is observed from Pluto as eternally hanging in the sky in the same place.

Asteroids

In addition to 9 planets, several dozen of their satellites and the rings of 4 giant planets, the Solar System includes a ring of a huge number of small planets, which were originally named among astronomers for their appearance asteroids- star-like. The asteroid belt occupies a wide strip between the orbits of Mars and Jupiter, as if marking the boundary between the terrestrial planets and the giant planets. For a long time there was an idea that the asteroid belt represents a kind of “quarry” of the Solar system. It was believed that it arose on the site of a full-fledged planet, which was crushed due to the strong influence of the nearby giant Jupiter. However, an analysis of the characteristics of the movement of many asteroids - and some of them either come very close to the Sun, or, conversely, move away to the outer edge of the Solar system - and a number of other facts indicated that the asteroids could not have arisen from a single planet. Most likely, this is the “construction debris” of a failed planet, traces of matter from a preplanetary cloud. The first of the asteroids was discovered on January 1, 1801 and was named Ceres. By the end of 1985 total number The number of asteroids registered by astronomers was 3,300. It is estimated that the total number of asteroids with a diameter of more than 1 km exceeds 1 million.

All the planets of the solar system revolve around the sun in such a way that they never move far from the plane passing through the solar equator. This orderliness does not apply to the movement of small planets - asteroids. The orbits of some of them are inclined to the plane of the solar equator by several tens of degrees.

Some famous asteroids:

• Ceres
• Pallas
• Juno
• Vesta
• Astraea
• Flora
• Metis
• Victoria
• Eunomia
• Melpomene
• Massalia
• Nausicaa
• Bamberg
• Aquitaine
• Papagena
• David
• Hidalgo
• Ganymede

Comets

What are comets? Pale celestial objects with huge tails, appearing from time to time on the earth's horizon like tongues of heavenly flame, captured the imagination of people and inspired superstitious horror in ancient times. They were considered harbingers of misfortune, formidable signs of God's wrath. Chroniclers from all parts of the world diligently noted the appearance of tailed monsters in their chronicles, and such records served scientists with invaluable service. Newton's contemporary Edmond Halley was the first astronomer to establish that at least some comets orbit the Sun and therefore regularly approach the Earth. The frequency of return to Earth, on average every 76 years, was reliably established for the first time for a bright comet, which was called Halley's Comet.

Ground-based studies have led to the conclusion that the internal structure of comets can be described by the “dirty snowball” model. It turned out that the comet's nucleus consists of frozen gases and water vapor ("snow") mixed with rock and metal particles ("dirt"). As the “snowball” approaches the Sun, the “snow” evaporates, forming the coma and tail of the comet. Due to the pressure of solar rays, the tails of comets are always directed away from the Sun, and a comet moving away from the Sun moves in interplanetary space with its tail first.

In 1986, a whole flotilla of spacecraft passed near Halley's Comet: the Soviet Vega-1 and Vega-2, the European Space Agency's Giotto probe, and two Japanese spacecraft Hakigake and Suisei. Photographs captured the nucleus of Comet Halley , which resembles a potato - a homogeneous body of irregular shape with craters and hills about 14 km long and 7 km in diameter. This is the size of many asteroids and small satellites of planets. Just as a potato is protected by a dense skin, the comet’s nucleus is surrounded by a dark dust crust. which from time to time powerful jets of gas burst into the surrounding space, feeding the coma and tail.

Meteors and meteorites

During the growth of planets from a preplanetary gas-dust cloud, the space between them was not completely cleared: “flakes” of matter still remained there. Additional debris appeared between the planets due to the scattering of comets. There are so many different particles of matter in interplanetary space today that from time to time they burst into the Earth’s atmosphere, heat up in it due to friction and burn out. Astronomers call a “shooting star” - the trace of an extraterrestrial guest that burned up in the atmosphere meteor. And if such a heavenly guest reaches the surface of the Earth, he is called meteorite. The weight of meteorites ranges from a few grams to tens of thousands of kilograms.

Scientists say that approximately 65 million years ago on Earth in short term The huge land reptiles collectively known as dinosaurs ceased to exist. One hypothesis connects the mass extinction of dinosaurs with the fall of an asteroid or gigantic meteorite to Earth.

A swarm of comet remnants moving in an elliptical orbit around the Sun and causing meteor showers when the shower crosses the Earth.