Space has attracted people's attention for a long time. Astronomers began to study the planets of the solar system in the Middle Ages, looking at them through primitive telescopes. But a thorough classification, description of the features of the structure and movement of celestial bodies became possible only in the 20th century. With the advent of powerful equipment, state-of-the-art observatories and spacecraft, several previously unknown objects were discovered. Now each student can list all the planets of the solar system in order. Almost all of them have been landed by a space probe, and so far man has only been to the Moon.
What is the solar system
The universe is huge and includes many galaxies. Our solar system is part of a galaxy with over 100 billion stars. But there are very few that look like the Sun. Basically, they are all red dwarfs, which are smaller in size and do not shine as brightly. Scientists have suggested that the solar system was formed after the emergence of the sun. Its huge field of attraction captured a gas-dust cloud, from which, as a result of gradual cooling, particles of solid matter were formed. Over time, celestial bodies formed from them. It is believed that the Sun is now in the middle of its life path, so it will exist, as well as all celestial bodies dependent on it, for several billion more years. Near space has been studied by astronomers for a long time, and any person knows what planets of the solar system exist. Photos of them, taken from space satellites, can be found on the pages of various information resources dedicated to this topic. All celestial bodies are held by the Sun's strong gravitational field, which makes up over 99% of the solar system's volume. Large celestial bodies revolve around the star and around their axis in one direction and in one plane, which is called the plane of the ecliptic.
Solar system planets in order
In modern astronomy, it is customary to consider celestial bodies, starting from the Sun. In the 20th century, a classification was created, which includes 9 planets of the solar system. But recent space exploration and the latest discoveries have prompted scientists to revise many positions in astronomy. And in 2006, at the international congress, due to its small size (a dwarf, not exceeding three thousand km in diameter), Pluto was excluded from the number of classical planets, and eight of them remained. Now the structure of our solar system has taken on a symmetrical, slender appearance. It includes four terrestrial planets: Mercury, Venus, Earth and Mars, then comes the asteroid belt, followed by four giant planets: Jupiter, Saturn, Uranus and Neptune. On the outskirts of the solar system also passes which scientists called the Kuiper belt. This is where Pluto is located. These places are still little studied because of their remoteness from the Sun.
Features of the terrestrial planets
What makes it possible to attribute these celestial bodies to one group? We list the main characteristics of the inner planets:
- relatively small size;
- hard surface, high density and similar composition (oxygen, silicon, aluminum, iron, magnesium and other heavy elements);
- the presence of an atmosphere;
- the same structure: a core of iron with nickel impurities, a mantle consisting of silicates, and a crust of silicate rocks (except for Mercury - it has no crust);
- a small number of satellites - only 3 for four planets;
- rather weak magnetic field.
Features of the giant planets
As for the outer planets, or gas giants, they have the following similar characteristics:
- large size and weight;
- they do not have a solid surface and are composed of gases, mainly helium and hydrogen (which is why they are also called gas giants);
- a liquid core consisting of metallic hydrogen;
- high rotation speed;
- a strong magnetic field, which explains the unusual nature of many processes occurring on them;
- there are 98 satellites in this group, most of which belong to Jupiter;
- The most characteristic feature of gas giants is the presence of rings. All four planets have them, although they are not always noticeable.
The first planet is Mercury
It is located closest to the Sun. Therefore, from its surface, the luminary looks three times larger than from the Earth. This also explains the strong temperature fluctuations: from -180 to +430 degrees. Mercury is moving very fast in its orbit. Maybe that's why he got such a name, because in Greek mythology, Mercury is the messenger of the gods. There is almost no atmosphere here, and the sky is always black, but the Sun shines very brightly. However, there are places at the poles where its rays never hit. This phenomenon can be explained by the tilt of the axis of rotation. No water was found on the surface. This circumstance, as well as the anomalously high daytime temperature (as well as the low nighttime temperature) fully explain the fact that there is no life on the planet.
Venus
If we study the planets of the solar system in order, then the second one is Venus. People could observe her in the sky in ancient times, but since she was shown only in the morning and in the evening, it was believed that these were 2 different objects. By the way, our Slavic ancestors called her Flicker. It is the third brightest object in our solar system. Previously, people called it the morning and evening star, because it is best seen before sunrise and sunset. Venus and Earth are very similar in structure, composition, size and gravity. Around its axis, this planet moves very slowly, making a complete revolution in 243.02 Earth days. Of course, the conditions on Venus are very different from those on Earth. It is twice as close to the Sun, so it is very hot there. The high temperature is also explained by the fact that thick clouds of sulfuric acid and an atmosphere of carbon dioxide create a greenhouse effect on the planet. In addition, the pressure at the surface is 95 times greater than on Earth. Therefore, the first ship that visited Venus in the 70s of the 20th century survived there for no more than an hour. A feature of the planet is also the fact that it rotates in the opposite direction, compared to most planets. Astronomers know nothing more about this celestial object yet.
Third planet from the Sun
The only place in the solar system, and indeed in the entire universe known to astronomers, where life exists, is the Earth. In the terrestrial group, it has the largest dimensions. What else is her
- The largest gravity among the terrestrial planets.
- Very strong magnetic field.
- High density.
- It is the only one among all the planets that has a hydrosphere, which contributed to the formation of life.
- It has the largest, in comparison with its size, satellite, which stabilizes its tilt relative to the Sun and affects natural processes.
The planet Mars
It is one of the smallest planets in our galaxy. If we consider the planets of the solar system in order, then Mars is the fourth from the Sun. Its atmosphere is very rarefied, and the pressure on the surface is almost 200 times less than on Earth. For the same reason, very strong temperature drops are observed. The planet Mars is little studied, although it has long attracted the attention of people. According to scientists, this is the only celestial body on which life could exist. After all, in the past there was water on the surface of the planet. This conclusion can be drawn from the fact that there are large ice caps at the poles, and the surface is covered with many furrows, which could be dried up river beds. In addition, there are some minerals on Mars that can only be formed in the presence of water. Another feature of the fourth planet is the presence of two satellites. Their unusualness is that Phobos gradually slows down its rotation and approaches the planet, while Deimos, on the contrary, moves away.
What is Jupiter famous for?
The fifth planet is the largest. 1300 Earths would fit in the volume of Jupiter, and its mass is 317 times more than the earth. Like all gas giants, its structure is hydrogen-helium, reminiscent of the composition of stars. Jupiter is the most interesting planet that has many characteristic features:
- it is the third brightest celestial body after the Moon and Venus;
- Jupiter has the strongest magnetic field of all the planets;
- it completes a full rotation around its axis in just 10 earth hours - faster than other planets;
- an interesting feature of Jupiter is a large red spot - this is how an atmospheric vortex is visible from the Earth, rotating counterclockwise;
- like all giant planets, it has rings, though not as bright as those of Saturn;
- this planet has the largest number of satellites. He has 63 of them. The most famous are Europa, on which water was found, Ganymede - the largest satellite of the planet Jupiter, as well as Io and Calisto;
- another feature of the planet is that in the shade the surface temperature is higher than in places illuminated by the Sun.
Planet Saturn
This is the second largest gas giant, also named after the ancient god. It consists of hydrogen and helium, but traces of methane, ammonia and water have been found on its surface. Scientists have found that Saturn is the most rarefied planet. Its density is less than that of water. This gas giant rotates very quickly - it completes one revolution in 10 Earth hours, as a result of which the planet is flattened from the sides. Huge speeds on Saturn and near the wind - up to 2000 kilometers per hour. It's more than the speed of sound. Saturn has another distinctive feature - it holds 60 satellites in its field of attraction. The largest of them - Titan - is the second largest in the entire solar system. The uniqueness of this object lies in the fact that, exploring its surface, scientists first discovered a celestial body with conditions similar to those that existed on Earth about 4 billion years ago. But the most important feature of Saturn is the presence of bright rings. They encircle the planet around the equator and reflect more light than itself. Four is the most amazing phenomenon in the solar system. Unusually, the inner rings move faster than the outer ones.
- Uranus
So, we continue to consider the planets of the solar system in order. The seventh planet from the Sun is Uranus. It is the coldest of all - the temperature drops to -224 ° C. In addition, scientists did not find metallic hydrogen in its composition, but found modified ice. Because Uranus is classified as a separate category of ice giants. An amazing feature of this celestial body is that it rotates while lying on its side. The change of seasons on the planet is also unusual: winter reigns there for 42 Earth years, and the Sun does not appear at all, summer also lasts 42 years, and the Sun does not set at this time. In spring and autumn, the luminary appears every 9 hours. Like all giant planets, Uranus has rings and many satellites. As many as 13 rings revolve around it, but they are not as bright as those of Saturn, and the planet holds only 27 satellites. If we compare Uranus with the Earth, then it is 4 times larger than it, 14 times heavier and is located at a distance from the Sun, in 19 times greater than the path to the luminary from our planet.
Neptune: the invisible planet
After Pluto was excluded from the number of planets, Neptune became the last from the Sun in the system. It is located 30 times farther from the star than the Earth, and is not visible from our planet even through a telescope. Scientists discovered it, so to speak, by chance: observing the peculiarities of the movement of the planets closest to it and their satellites, they concluded that there must be another large celestial body beyond the orbit of Uranus. After discovery and research, interesting features of this planet were revealed:
- due to the presence of a large amount of methane in the atmosphere, the color of the planet from space appears blue-green;
- Neptune's orbit is almost perfectly circular;
- the planet rotates very slowly - it completes one circle in 165 years;
- Neptune is 4 times larger than the Earth and 17 times heavier, but the force of attraction is almost the same as on our planet;
- the largest of the 13 moons of this giant is Triton. It is always turned to the planet on one side and slowly approaches it. Based on these signs, scientists have suggested that it was captured by Neptune's gravity.
In the entire galaxy, the Milky Way is about a hundred billion planets. So far, scientists cannot even study some of them. But the number of planets in the solar system is known to almost all people on Earth. True, in the 21st century, interest in astronomy has faded a little, but even children know the name of the planets of the solar system.
Questions:
1. Structure and composition of the solar system.
2. The birth of the solar system.
3. Planets of the Earth group: Mercury, Venus, Mars.
4. Planets of the Jupiter group.
5. The moon is a satellite of the Earth.
1. Structure and composition of the solar system
The solar system is a particle in the Milky Way galaxy.
The solar system is a system of celestial bodies welded together by the forces of mutual attraction. The planets included in the system move in almost the same plane and in the same direction in an elliptical orbit.
The existence of the solar system was first announced in 1543 by the Polish astronomer Nicolaus Copernicus, refuting the notion that had prevailed for several centuries that the Earth was the center of the universe.
The center of the solar system is the ordinary star the Sun, in which the bulk of the system's matter is concentrated. Its mass is 750 times the mass of all the planets in the solar system and 330,000 times the mass of the Earth. Under the influence of the gravitational attraction of the Sun, the planets form a group, rotating around its axis (each with its own speed) and making a revolution around the Sun without deviating from its orbit. The elliptical orbits of the planets are at different distances from our star.
The order of the planets:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
According to physical characteristics, the large 8 planets are divided into two groups: the Earth and Mercury, Mars and Venus similar to it. The second group includes the giant planets: Jupiter, Saturn, Uranus and Neptune. The most distant planet Pluto, as well as 3 more planets discovered since 2006, are classified as minor planets of the solar system.
Planets of the 1st group (terrestrial type) consist of dense rocks, and the second - of gas, ice and other particles.
2. The birth of the solar system.
In the inner heated regions, dense blocks formed and coalesced with each other, forming terrestrial-type planets. Dust particles collided, broke up and stuck together again, forming lumps. They were too small, had a small gravitational field and could not attract the light gases hydrogen and helium. As a result, planets of the 1st type are small in volume, but very dense.
Farther from the center of the disk, the temperature was much lower. Volatile substances adhered to dust particles. The high content of hydrogen and helium served as the basis for the formation of giant planets. The planets formed there attracted gases to themselves. Currently, they also have extensive atmospheres.
Part of the gas and dust cloud turned into meteorites and comets. The constant bombardment of cosmic bodies by meteorites is a continuation of the process of formation of the Universe.
How did the solar system originate?
3. Planets of the Earth group: Mercury, Venus, Mars.
All terrestrial planets have a lithosphere - a solid shell of the planet, including the earth's crust and part of the mantle.
Venus, Mars, like the Earth, have an atmosphere that is similar in the presence of chemical elements to each other. The difference is only in the concentration of substances. On Earth, the atmosphere has changed due to the activity of living organisms. The basis of the atmosphere of Venus and Mars is carbon dioxide - 95%, and the Earth - nitrogen. The density of the Earth's atmosphere is 100 times less than Venus and 100 times greater than Mars. The clouds of Venus are concentrated sulfuric acid. A large amount of carbon dioxide can create a greenhouse effect, which is why there are such high temperatures.
planet X atmospheres | Venus | Earth | Mars |
|||
The main constituents of the atmosphere | N 2 O 2 CO2 H2O | 3-5% 0,0 01 95 -97 0 , 01-0 , 1 0 , 01 | N 2 O2 CO2 H2O |
0,03 0,1-1 0,93 | N 2 O2 CO2 H2O | 2-3% 0,1-0,4 0,001-0,1 |
Surface pressure (atm.) | 0,006 |
|||||
Surface Temperature (Rf. Lat.) | +40 to -30 about C | 0 to - 70 about C |
||||
Comparison of the sizes of the terrestrial planets (from left to right - Mercury, Venus, Earth, Mars)
Mercury.
Distance to the Sun: 57.9 million km
Diameter: 4.860 km
Period of rotation around the axis (day): 176
Per. revolutions around the Sun (year): 88 days.
Temperature: + 350-426 about C on the sunny side and - 180 about C for the night.
There is almost no atmosphere, there is a very weak magnetic field.
The average speed of the planet in orbit is 48 km / s, constantly changing. The axis of rotation of the planet is at almost a right angle to the plane of the orbit. The surface of Mercury is similar to the Moon. The surface was formed by volcanic activity and meteorite impacts due to the absence of an atmosphere. Craters vary in size from a few meters to hundreds of kilometers across. The largest crater on Mercury is named after the great Dutch painter Rembrandt, its diameter is 716 km. The phases of the moon are observed through a telescope. There are lowlands - "seas" and uneven hills - "continents". Mountain ranges reach a height of several kilometers. The sky on Mercury is black due to the highly rarefied atmosphere, which is almost non-existent.
Mercury has a large iron core, a rocky mantle, and a crust.
Venus.
Distance to the Sun: 108 million km
Diameter 12104 km
243 days
225 days
Axis of rotation vertical
Temperature: average + 464 about S.
Atmosphere: CO 2 97%.
Rotates clockwise
There are vast plateaus on Venus, mountain ranges located on them rise to a height of 7-8 km. The highest mountains are 11 km. There are traces of tectonic and volcanic activity. About 1000 craters of meteorite origin. 85% of the planet's surface is occupied by volcanic plains.
The surface of Venus is hidden by a dense cloud layer of sulfuric acid. The sun is barely visible in the dark orange sky. At night, the stars are not visible at all. Clouds go around the planet in 4-5 days. The thickness of the atmosphere is 250 km.
Structure of Venus: solid metal core, silicate mantle and crust. The magnetic field is almost absent.
Mars.
Distance to the Sun: 228 million km
Diameter: 6794km
Period of rotation around the axis (day): 24 h 37 min
Per. revolution around the Sun (year): 687 days
Temperature:Average - 60 about C;at the equator 0 o C; at the poles - 140 o C
Atmosphere: CO 2, the pressure is 160 times less than Earth's.
Moons: Phobos, Deimos.
The axial tilt of Mars is 25 degrees.
On the surface of Mars, one can distinguish "seas" of 2000 km and elevated areas - "continents". In addition to meteorite craters, giant volcanic cones 15-20 km high and 500-600 km in diameter have been discovered - Mount Olympus. The Mariner Valley is a giant canyon visible from space. Mountain ranges and canyons have been discovered. Screes, dunes, and other formations of atmospheric erosion speak of dust storms. The red color of Martian dust is the presence of iron oxide (limonite substance). Valleys that look like dry riverbeds are evidence that Mars was once warmer and water existed. She is still in the polar ice. And oxygen is in oxides.
The largest meteorite crater in the solar system has been discovered in the northern hemisphere of Mars. Its length is 10.6 thousand km, and its width is 8.5 thousand km.
The change of seasons causes the melting of the Martian glaciers, accompanied by the release of carbon dioxide and an increase in pressure in the atmosphere. As a result, winds and hurricanes appear, the speed of which reaches 10-40, and sometimes 100 m/s.
The structure of Mars: there is an iron core, mantle and crust.
Mars has two moons that are irregularly shaped. They are composed of carbon-rich rock and are thought to be asteroids captured by the gravity of Mars. The diameter of Phobos is about 27 km. It is the largest and closest satellite to Mars. The diameter of Deimos is about 15 km.
4. Planets of the Jupiter group
Distance to the Sun: 778 million km
Diameter: 143thousand km
Period of rotation around the axis (day): 9 h 50 min
Per. revolutions around the Sun (year): » 12 years
Temperature: -140 about C
Atmosphere: Hydrogen, methane, ammonia, helium.
A ring of dust and stones is barely noticeable
Satellites: 67 - Ganymede, Io, Europa, Callisto, etc.
The planet is rotating very fast. The axis is slightly tilted. Structure:
liquid hydrogen, liquid metallic hydrogen, iron core.
The atmosphere is gaseous: 87% consists of hydrogen, ammonia and helium are present. High pressure. Clouds of reddish ammonia, severe thunderstorms. The thickness of the cloud layer is 1000 km. Wind speed 100 m/s (650 km/h), cyclones (Great Red Spot 30 thousand km wide). The planet radiates heat, but thermonuclear reactions do not occur in the center, as in the Sun.
The rapid rotation of Jupiter and the heat emanating from within give rise to powerful atmospheric movements. Belts with different pressures (bands) appear in the atmosphere, hurricanes rage. The surface is liquid hydrogen with a temperature of –140 °C, seething. The density is 4 times less than the density of water - 1330 kg/m3. Inside the hydrogen ocean, the temperature is +11,000 °C. Liquefied hydrogen under high pressure becomes metallic (very dense), creates a strong magnetic field. The temperature of the core is 30 thousand ° C, it consists of iron.
Jupiter has a barely visible ring of dust and rocks. Reflecting from the ring, sunlight creates a halo - a glow. You cannot see the ring through a telescope - it is perpendicular.
As of January 2012, Jupiter has 67 known moons - the largest number among the planets of the solar system. The largest: 
And about- the closest, makes a revolution around Jupiter in 42.5 hours. The density is high, there is iron in the core. Similar in size to the moon. Io is volcanically active, observation. 12 active volcanoes. Sulfur compounds colored the surface yellow-orange. The surface temperature near the volcanoes is 300 °C. Black seas of molten sulfur sway on the orange shores. It always faces Jupiter on the same side. Forms 2 tidal humps due to the force of gravity, which move, which led to the heating of the bowels.
Europe smaller than Io. It has a smooth surface, consisting of frozen water ice, dotted with cracks and streaks. The core is silicate, there are few craters. Europe is young in age - about 100 million years.
Ganymede is the largest satellite in the solar system. Its radius is 2.631 km. 4% of the surface is ice crust covered with craters. Age like Io. It has a stone core and a mantle of water ice. On the surface lies stone-ice dust.
Callisto is the 2nd largest moon of Jupiter. The surface is icy, heavily cratered, similar to Ganymede.
All satellites face Jupiter on the same side.
Saturn
Distance to the Sun: 9.54 AU (1 AU = 150 million km - the distance from the Earth to the Sun, used for long distances)
Diameter: 120.660 km
Period of rotation around the axis (day): 10.2 h
Per. revolutions in the district of the Sun (year): » 29.46 years old
Temperature: -180 about C
Atmosphere: Hydrogen 93%, methane, ammonia, helium.
Surface made of liquid hydrogen and helium
Satellites: 62.
Saturn is a light yellow ball of gas, composed of hydrogen and helium (mostly liquid molecular hydrogen). Due to the rapid rotation, the ball is strongly flattened at the poles. Day - 10 h 16 min. The core is made of iron. Saturn has a strong magnetic field generated by metallic hydrogen in the mantle. The surface of Saturn is liquid hydrogen. Ammonia crystals are concentrated near the surface, which prevent from seeing the surface from space.
Structure: core, liquid metallic hydrogen, liquid hydrogen, atmosphere.
The structure of the atmosphere is almost like that of Jupiter. It consists of 94-93% hydrogen, helium, ammonia, methane, water, impurities of phosphorus and other elements. Bands parallel to the equator are observed - giant atmospheric currents, the speed of which is 500 m / s.
Saturn has rings - the remains of a huge circumplanetary cloud, consisting of dust particles, ice and stones. The rings are younger than the planet. It is believed that these are the remains of an exploded satellite or a comet captured by Saturn. Banding is determined by the composition of the rings. The rings sway and bend under the gravitational pressure of the satellites. Particle speed 10 km/s. Lumps constantly collide and crumble, sticking together again. Their structure is loose. The thickness of the rings is 10-20 m, and the width is 60 thousand km.
Saturn has 62 moons made up of light-colored water ice. The satellites always face Saturn on the same side. Mimas has a huge crater 130 km wide, Tethys has two of its satellites, and Dione has one. The largest moon of Saturn is Titan. (2nd after Ganymede). Its diameter is 5.150 km (greater than Mercury). In structure, it is similar to Jupiterian: a stone core and an icy mantle. It has a powerful atmosphere of nitrogen and methane. The surface is an ocean of methane -180 °C. Phoebe is a distant satellite of Saturn that rotates in the opposite direction.
Uranus
Diameter: 51.200 km
Period of rotation around the axis (day): » 17h
Per. converted ia around the sun (year): 84 years old
Temperature: -218 °C
Atmosphere: hydrogen and helium - the main components, methane, ammonia, etc.
liquid hydrogen surface methane
Rings - 9 (11) rows
Satellites: 27 - Miranda, Ariel, Titania, Oberon, Umbriel and etc.
The planet is blue and green. This is due to the presence of methane in the atmosphere. Methane absorbs red light and reflects blue and green light. The atmosphere is made up of hydrogen, helium and methane. Its thickness is 8 thousand km. The surface is hidden from observation due to methane haze. The speed of clouds in the atmosphere is 10 m/s. The mantle of Uranus is a frozen ocean of water, ammonia and methane. Pressure 200 thousand earth atmospheres. The temperature is about - 200 °C. The iron silicate core has a temperature of 7.000°C.
Uranus has a strong magnetic field. Axis tilt 98°. Uranus has 27 satellites moving perpendicular to the orbit of the ecliptic. The most distant Oberon and Titania have an icy surface.
Uranus has narrow black rings arranged in 9 rows. They are made of stone. Thickness - tens of meters, with a radius of 40-50 thousand km. Satellites: 14 - Triton, Nereid, etc.
Similar in structure and composition to Uranus: core, icy mantle and atmosphere. Has a strong magnetic field. The atmosphere contains a lot of hydrogen, helium, and also more methane than Uranus, which is why the planet is blue. Atmospheric cyclones are noticeable - the Great Dark Spot with white clouds at the edges. On Neptune, the strongest winds in the solar system are 2200 km/h.
Neptune has 14 moons. Triton moves in the opposite direction to Neptune. Its diameter is 4950 km. It has an atmosphere, the surface temperature is 235-238 °C. Volcanically active - geysers.
Neptune has 4 rarefied narrow rings, which are visible to us in the form of arcs, because. maybe the substance is unevenly distributed. The rings are composed of ice particles or reddish silicates.
Structure: iron core, ice mantle and atmosphere (hydrogen, helium, methane). Pluto is a stone ball, the surface of which is covered with frozen gases - grayish methane ice. Planet diameter 2290 km . The atmosphere of methane and nitrogen is highly rarefied. The only satellite of Pluto is very large compared to the planet (Charon). Consists of water ice and reddish rocks. Surface temperature - 228 - 206°C. At the poles are caps of frozen gases. The sun from the surface of Pluto and Charon is seen in1000 times smaller than from Earth.
5. The moon is a satellite of the Earth
The only satellite of the Earth - the Moon lags behind it by 385,000 km. Glows with reflected light. Half the size of Pluto and nearly the size of Mercury. The diameter of the Moon is 3474 km (more than ¼ of the Earth). The mass is 1/81 of the mass of the Earth (7.34x1022 kg), and the force of gravity is 1/6 of the earth's gravity. The age of the Moon is 4.36 billion years. There is no magnetic field.
The moon makes a full revolution around the Earth in 27 days 7 hours 43 minutes. A day lasts 2 Earth weeks. There is no water and air on the Moon, therefore, on a lunar day, the temperature is + 120 ° C, and at night it drops to - 160 ° C.
The moon has a core and a thick crust about 60 km thick. Therefore, the Moon and the Earth have a similar origin. An analysis of the soil delivered by American astronauts on the Apollo spacecraft showed that it contains minerals similar to those of the earth. The soil is poorer in terms of the amount of minerals, because. there is no water that creates oxides.
Samples of lunar rock indicate that it was formed from a molten, cooled and crystallized mass. Lunar soil - regolith - is a finely divided substance formed as a result of constant bombardment of the surface by cosmic bodies. The surface of the moon is dotted with craters (there are 30 thousand of them). One of the large craters is located on the far side of the satellite, it reaches 80 km in diameter. The craters are named after famous scientists, figures from different eras: Plato, Aristotle, Copernicus, Galileo, Lomonosov, Gagarin, Pavlov and others.
The light areas of the Moon are called "land", and the dark areas - depressions - "seas" (Ocean of Storms, Sea of Rains, Sea of Tranquility, Gulf of Heat, Sea of Crises, etc.). There are mountains and even mountain ranges on the Moon. They are named as on Earth: the Alps, the Carpathians, the Caucasus, the Pyrenees.
On the Moon, surface cracking can be observed due to sudden temperature changes, moonquakes. In the cracks - frozen lava.
There are three hypotheses for the origin of the moon.
1. "Capture". A space body flying past was captured by the forces of gravity of the Earth and turned into a satellite.
2 sisters". The Earth and the Moon were formed from one clot of matter, but each developed on its own in close proximity to each other.
3. "Mother and daughter." Once upon a time, part of the matter separated from the Earth, leaving a deep depression (in the place of the Pacific Ocean). Space images of the Moon's surface and analysis of the soil show that it was formed under the influence of high temperatures as a result of the impact of cosmic bodies. This means that this separation occurred a very long time ago. According to this hypothesis, 4 billion years ago, a huge asteroid or a small planet crashed into the Earth. Broken off pieces of the earth's crust and the "wanderer" scattered into debris into space. Under the influence of gravitational forces, a satellite formed over time. The correctness of this hypothesis is proved by two facts: a small amount of iron on the Moon and the presence of two dust satellites rotating in a lunar orbit (observed in 1956).
Origin of the Moon
The moon also influences the earth. It affects our well-being, causes ebb and flow. This is due to the strengthening of the action of the Moon by the Sun when they are in the same plane.
The lunar face is constantly changing. This is due to the different position of the moon relative to the luminary.
A full cycle of the phase of the moon takes 29.5 days. Each phase lasts about a week.
1. New Moon - The moon is not visible.
2. First quarter - from a thin crescent on the right to a semicircle.
3. Full moon - round moon.
4. Last quarter - reduction from half to a narrow crescent.
Moon eclipse occurs when the Earth is in a straight line between the Sun and the Moon. The moon is in the shadow of the earth. The earth's atmosphere allows only red rays to reach the moon, so the moon appears red. This event lasts approximately one and a half hours.
solar eclipsehappens when The Moon covers the Sun with its disk. A total eclipse at one point on the globe is rare. You can see partial solar eclipses, which are more common. The shadow of the moon has length 250 km . Duration 7 min 40 sec.
Welcome to the astronomy portal site dedicated to our Universe, space, large and small planets, star systems and their components. Our portal provides detailed information about all 9 planets, comets, asteroids, meteors and meteorites. You can learn about the origin of our Sun and the Solar System.
The sun, together with the nearest celestial bodies that revolve around it, form the solar system. The number of celestial bodies includes 9 planets, 63 satellites, 4 rings of giant planets, more than 20 thousand asteroids, a huge number of meteorites and millions of comets. Between them there is a space in which electrons and protons (particles of the solar wind) move. Although scientists and astrophysicists have been studying our solar system for a long time, there are still unexplored places. For example, most of the planets and their satellites have been studied only briefly from photographs. We saw only one hemisphere of Mercury, and no space probe flew to Pluto at all.
Almost the entire mass of the solar system is concentrated in the Sun - 99.87%. The size of the Sun in the same way exceeds the size of other celestial bodies. This is a star that shines on its own due to high surface temperatures. The planets surrounding it shine with the light reflected from the Sun. This process is called albedo. There are nine planets in total - Mercury, Venus, Mars, Earth, Uranus, Saturn, Jupiter, Pluto and Neptune. Distance in the solar system is measured in units of our planet's average distance from the sun. It is called an astronomical unit - 1 a.u. = 149.6 million km. For example, the distance from the Sun to Pluto is 39 AU, but sometimes this figure increases to 49 AU.
The planets revolve around the Sun in almost circular orbits that lie relatively in the same plane. In the plane of the Earth's orbit lies the so-called plane of the ecliptic, very close to the average of the plane of the orbits of the other planets. Because of this, the visible paths of the planets of the Moon and the Sun in the sky lie near the line of the ecliptic. The inclinations of the orbits begin their reading from the plane of the ecliptic. Those angles that have an inclination of less than 90⁰ correspond to counterclockwise motion (forward orbital motion), and angles greater than 90⁰ correspond to reverse motion.
In the solar system, all planets move in a forward direction. Pluto's largest orbital inclination is 17⁰. Most comets move in the opposite direction. For example, the same comet Halley - 162⁰. All the orbits of the bodies that are in our solar system are basically elliptical. The closest point of the orbit to the Sun is called perihelion, and the farthest point is called aphelion.
All scientists, taking into account terrestrial observation, divide the planets into two groups. Venus and Mercury, as the planets closest to the Sun, are called internal, and more distant external. The inner planets have a limiting angle of removal from the Sun. When such a planet is at its maximum east or west of the Sun, astrologers say that it is located at its greatest east or west elongation. And if the inner planet is visible in front of the Sun, it is located in inferior conjunction. When behind the Sun, it is in superior conjunction. Just like the Moon, these planets have certain phases of illumination during the synodic period Ps. The true orbital period of planets is called sidereal.
When an outer planet is behind the Sun, it is in conjunction. In the event that it is placed in the opposite direction to the Sun, it is said to be in opposition. That planet, which is observed at an angular distance of 90⁰ from the Sun, is considered as quadrature. The asteroid belt between the orbits of Jupiter and Mars divides the planetary system into 2 groups. The inner ones refer to the planets of the Earth group - Mars, Earth, Venus and Mercury. Their average density is from 3.9 to 5.5 g/cm 3 . They are devoid of rings, slowly rotate along the axis and have a small number of natural satellites. Earth has the Moon, and Mars has Deimos and Phobos. Behind the asteroid belt are the giant planets - Neptune, Uranus, Saturn, Jupiter. They are characterized by large radius, low density and deep atmosphere. There is no solid surface on such giants. They rotate very quickly, are surrounded by a large number of satellites and have rings.
In ancient times, people knew the planets, but only those that were visible to the naked eye. In 1781, V. Herschel discovered another planet - Uranus. In 1801, G. Piazzi discovered the first asteroid. Neptune was discovered twice, first theoretically by W. Le Verrier and J. Adams, and then physically by I. Galle. Pluto as the most distant planet was discovered only in 1930. Galileo discovered four moons of Jupiter in the 17th century. Since that time, numerous discoveries of other satellites have begun. All of them were made with the help of telescopes. H. Huygens first learned about the fact that Saturn is surrounded by a ring of asteroids. Dark rings around Uranus were discovered in 1977. The remaining space discoveries were mainly made by special machines and satellites. So, for example, in 1979, thanks to the Voyager 1 probe, people saw the transparent stone rings of Jupiter. And 10 years later, Voyager 2 discovered the heterogeneous rings of Neptune.
Our portal site will tell you basic information about the solar system, its structure and celestial bodies. We present only cutting-edge information that is relevant at the moment. The Sun itself is one of the most important celestial bodies in our galaxy.
The sun is at the center of the solar system. This is a natural single star with a mass of 2 * 1030 kg and a radius of approximately 700,000 km. The temperature of the photosphere - the visible surface of the Sun - 5800K. Comparing the gas density of the Sun's photosphere with the density of air on our planet, we can say that it is thousands of times less. Inside the Sun, density, pressure, and temperature increase with depth. The deeper, the more indicators.
The high temperature of the Sun's core affects the conversion of hydrogen into helium, resulting in a large amount of heat being released. Because of this, the star does not shrink under the influence of its own gravity. The energy that is released from the core leaves the Sun in the form of radiation from the photosphere. Radiation power - 3.86 * 1026 W. This process has been going on for about 4.6 billion years. According to approximate estimates of scientists, about 4% has already been processed from hydrogen into helium. Interestingly, 0.03% of the mass of the Star is converted into energy in this way. Considering the models of the life of the Stars, it can be assumed that the Sun has now passed half of its own evolution.
The study of the Sun is extremely difficult. Everything is connected precisely with high temperatures, but thanks to the development of technology and science, humanity is gradually mastering knowledge. For example, in order to determine the content of chemical elements on the Sun, astronomers study radiation in the light spectrum and absorption lines. Emission lines (emission lines) are very bright parts of the spectrum that indicate an excess of photons. The frequency of the spectral line indicates which molecule or atom is responsible for its appearance. The absorption lines are represented by dark gaps in the spectrum. They indicate missing photons of one frequency or another. And that means they are absorbed by some chemical element.
By studying the thin photosphere, astronomers estimate the chemical composition of its depths. The outer regions of the Sun are mixed by convection, the solar spectra are of high quality, and the physical processes responsible for them are explainable. Due to the lack of funds and technologies, only half of the lines of the solar spectrum have been intensified so far.
The sun is made up of hydrogen, followed by helium. It is an inert gas that does not react well with other atoms. Similarly, it is reluctant to show up in the optical spectrum. Only one line is visible. The entire mass of the Sun is 71% hydrogen and 28% helium. The remaining elements occupy a little more than 1%. Interestingly, this is not the only object in the solar system that has the same composition.
Sunspots are regions of the surface of a star with a large vertical magnetic field. This phenomenon prevents the gas from moving vertically, thereby suppressing convection. The temperature of this region drops by 1000 K, thus forming a spot. Its central part - "shadow", is surrounded by a higher temperature area - "penumbra". In size, such a spot in diameter slightly exceeds the size of the Earth. Its viability does not exceed a period of several weeks. There is no fixed number of sunspots. There may be more in one period and less in another. These periods have their own cycles. On average, their figure reaches 11.5 years. The viability of stains depends on the cycle, the longer it is, the less stains exist.
Fluctuations in the activity of the Sun practically do not affect the total power of its radiation. Scientists have long tried to find a link between Earth's climate and sunspot cycles. This solar phenomenon is associated with the event - "Maunder minimum". In the middle of the 17th century, for 70 years, our planet experienced the Little Ice Age. At the same time as this event, there was practically no spot on the Sun. Until now, it is not known exactly whether there is a connection between these two events.
In total, there are five large constantly rotating hydrogen-helium balls in the solar system - Jupiter, Saturn, Neptune, Uranus and the Sun itself. Inside these giants are almost all the substances of the solar system. Direct study of distant planets is not yet possible, so most of the unproven theories remain unproven. The same situation is with the bowels of the Earth. But people still found a way to somehow study the internal structure of our planet. Seismologists cope well with this issue by observing seismic tremors. Naturally, their own methods are quite applicable to the Sun. Unlike seismic terrestrial movements, constant seismic noise acts in the Sun. Under the converter zone, which occupies 14% of the Star's radius, matter rotates synchronously with a period of 27 days. Higher in the convective zone, rotation proceeds synchronously along cones of equal latitude.
More recently, astronomers have tried to apply seismological methods to the study of giant planets, but there have been no results. The fact is that the instruments used in this study cannot yet fix the emerging oscillations.
Above the photosphere of the Sun there is a thin, very hot layer of the atmosphere. It can only be seen during solar eclipses. It is called the chromosphere because of its red color. The chromosphere is about several thousand kilometers thick. From the photosphere to the top of the chromosphere, the temperature doubles. But it is still unknown why the energy of the Sun is released, leaves the chromosphere in the form of heat. The gas that is above the chromosphere is heated to one million K. This region is also called the corona. Along the radius of the Sun, it extends for one radius and has a very low density of gas inside it. Interestingly, at low gas density, the temperature is very high.
From time to time, gigantic formations are created in the atmosphere of our star - eruptive prominences. Having the shape of an arch, they rise from the photosphere to a great height of about half the solar radius. According to the observations of scientists, it turns out that the shape of the prominences is constructed by lines of force emanating from the magnetic field.
Another interesting and extremely active phenomenon is solar flares. These are very powerful emissions of particles and energy lasting up to 2 hours. Such a flow of photons from the Sun to the Earth reaches in eight minutes, and protons and electrons reach in a few days. Such flashes are created in places where the direction of the magnetic field changes sharply. They are caused by the movement of substances in sunspots.
- The solar system is a system of celestial bodies welded together by the forces of mutual attraction, which is formed by 9 large planets with their satellites (more than 60 are already known), several thousand small planets (or asteroids), comets and meteoroids.
- Solar gravitation governs the motion of all other bodies. Only satellites revolve around their planets, the attraction of which, due to proximity, is stronger than the sun.
- The age of the solar system is 4.6 billion years. It was formed from a rotating gas and dust cloud, the compression of which gave rise to a central condensation, which then turned into the Sun.
- The planets are divided into 2 groups: the planets of the terrestrial group and the planets of the Jupiter, or giant planets.
- Terrestrial planets: Mercury, Venus, Earth, Mars were formed closer to the Sun, and have a high density, they consist mainly of silicon and iron compounds.
- Planets of the Jupiter group: Jupiter, Saturn, Uranus, Neptune are gas giants that formed in critically cold temperatures. Composed primarily of hydrogen and helium. The atmospheres of these planets are gradually condensing, gradually turning into a liquid mantle.
- Pluto does not fall under the scientific definition of the term "planet" since in size and properties it is close to the ice satellites of the giant planets.
- All planets revolve around the Sun in the same direction (straight). The orbits of the planets are close to circular in shape, and the planes of the orbits are close to the main plane of the solar system, called the “invariable Laplace plane”.
- Our solar system is located in the Orion arm of the Milky Way galaxy. There are likely billions of other solar systems in our Milky Way Galaxy. And there are billions of galaxies in the universe.
- We measure distance in our solar system in astronomical units (AU). One a.u. equals the distance between the Sun and the Earth, which is 149,597,870 km (93 million miles).
