The fourth planet from the sun. Sizes of the planets of the solar system
The science
We all know from childhood that at the center of our solar system is the Sun, around which the four closest terrestrial planets revolve, including Mercury, Venus, Earth and Mars. They are followed by four gas giant planets: Jupiter, Saturn, Uranus and Neptune.
After Pluto ceased to be considered a planet in the solar system in 2006 and became a dwarf planet, the number of main planets was reduced to 8.
Although many people know the general structure, there are many myths and misconceptions regarding the solar system.
Here are 10 facts you might not know about the solar system.
1. The hottest planet is not closest to the Sun
Many people know that Mercury is the planet closest to the Sun, whose distance is almost two times less than the distance from the Earth to the Sun. It's no wonder that many people believe that Mercury is the hottest planet.
In fact Venus is the hottest planet in the solar system- the second planet close to the Sun, where the average temperature reaches 475 degrees Celsius. This is enough to melt tin and lead. At the same time, the maximum temperature on Mercury is about 426 degrees Celsius.
But due to the lack of an atmosphere, the surface temperature of Mercury can vary by hundreds of degrees, while the carbon dioxide on the surface of Venus maintains a virtually constant temperature at any time of the day or night.
2. The edge of the solar system is a thousand times further from Pluto
We are used to thinking that the solar system extends to the orbit of Pluto. Today, Pluto is not even considered a major planet, but this idea remains in the minds of many people.
Scientists have discovered many objects orbiting the Sun that are much further than Pluto. These are the so-called trans-Neptunian or Kuiper belt objects. The Kuiper Belt extends over 50-60 astronomical units (An astronomical unit, or the average distance from the Earth to the Sun, is 149,597,870,700 m).
3. Almost everything on planet Earth is a rare element
The earth is mainly composed of iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, sodium and aluminum.
Although all of these elements have been found in different places throughout the universe, they are only traces of elements that dwarf the abundance of hydrogen and helium. Thus, the Earth is mostly composed of rare elements. This does not indicate any special place on planet Earth, since the cloud from which the Earth formed contained large amounts of hydrogen and helium. But because they are light gases, they were carried into space by the sun's heat as the Earth formed.
4. The solar system has lost at least two planets
Pluto was originally considered a planet, but due to its very small size (much smaller than our Moon), it was renamed a dwarf planet. Astronomers also the planet Vulcan was once believed to exist, which is closer to the Sun than Mercury. Its possible existence was discussed 150 years ago to explain some features of Mercury's orbit. However, later observations ruled out the possibility of Vulcan's existence.
In addition, recent research has shown that it may someday there was a fifth giant planet, similar to Jupiter, which orbited the Sun, but was thrown out of the Solar System due to gravitational interaction with other planets.
5. Jupiter has the largest ocean of any planet
Jupiter, which orbits in cold space five times farther from the sun than planet Earth, was able to retain much higher levels of hydrogen and helium during formation than our planet.
One could even say that Jupiter is mainly composed of hydrogen and helium. Given the planet's mass and chemical composition, as well as the laws of physics, under cold clouds, an increase in pressure should lead to the transition of hydrogen to a liquid state. That is, on Jupiter there should be deepest ocean of liquid hydrogen.
According to computer models, this planet not only has the largest ocean in the solar system, its depth is approximately 40,000 km, that is, equal to the circumference of the Earth.
6. Even the smallest bodies in the solar system have satellites
It was once believed that only large objects such as planets could have natural satellites or moons. The existence of moons is sometimes even used to determine what a planet actually is. It seems counterintuitive that small cosmic bodies could have enough gravity to hold a satellite. After all, Mercury and Venus don't have any, and Mars only has two tiny moons.
But in 1993, the Galileo interplanetary station discovered a Dactyl satellite near the asteroid Ida, only 1.6 km wide. Since then it has been found moons orbiting about 200 other small planets, which made defining a “planet” much more difficult.
7. We live inside the Sun
We usually think of the Sun as a huge hot ball of light located at a distance of 149.6 million km from Earth. In fact The Sun's outer atmosphere extends much further than the visible surface.
Our planet orbits within its thin atmosphere, and we can see this when gusts of solar wind cause the aurora to appear. In this sense, we live inside the Sun. But the solar atmosphere does not end on Earth. The aurora can be observed on Jupiter, Saturn, Uranus and even distant Neptune. The outermost region of the solar atmosphere is the heliosphere extends over at least 100 astronomical units. This is about 16 billion kilometers. But since the atmosphere is drop-shaped due to the movement of the Sun in space, its tail can reach from tens to hundreds of billions of kilometers.
8. Saturn isn't the only planet with rings
While Saturn's rings are by far the most beautiful and easy to observe, Jupiter, Uranus and Neptune also have rings. While Saturn's bright rings are made of icy particles, Jupiter's very dark rings are mostly dust particles. They may contain minor fragments of disintegrated meteorites and asteroids and possibly particles of the volcanic moon Io.
Uranus's ring system is slightly more visible than Jupiter's and may have formed after the collision of small moons. Neptune's rings are faint and dark, just like Jupiter's. Faint rings of Jupiter, Uranus and Neptune impossible to see through small telescopes from Earth, because Saturn became most famous for its rings.
Contrary to popular belief, there is a body in the solar system with an atmosphere essentially similar to that of Earth. This is Saturn's moon Titan.. It is larger than our Moon and is close in size to the planet Mercury. Unlike the atmosphere of Venus and Mars, which are much thicker and thinner, respectively, than that of Earth, and consist of carbon dioxide, Titan's atmosphere is mostly nitrogen.
The Earth's atmosphere is approximately 78 percent nitrogen. The similarity to the Earth's atmosphere, and especially the presence of methane and other organic molecules, led scientists to believe that Titan could be considered an analogue of the early Earth, or that some kind of biological activity was present there. For this reason, Titan is considered the best place in the solar system to search for signs of life.
Our home in space is the Solar System, a star system consisting of eight planets and part of the Milky Way galaxy. In the center is a star called the Sun. The solar system is four and a half billion years old. We live on the third planet from the sun. Do you know about other planets in the solar system?! Now we will tell you a little about them.
Mercury- the smallest planet in the solar system. Its radius is 2440 km. The period of revolution around the Sun is 88 Earth days. During this time, Mercury manages to rotate around its own axis only one and a half times. A day on Mercury lasts approximately 59 Earth days. The orbit of Mercury is one of the most unstable: not only the speed of movement and its distance from the Sun, but also the position itself changes there. There are no satellites.
Neptune- the eighth planet of the solar system. It is located quite close to Uranus. The radius of the planet is 24547 km. A year on Neptune is 60,190 days, that is, about 164 Earth years. Has 14 satellites. It has an atmosphere in which the strongest winds have been recorded - up to 260 m/s.
By the way, Neptune was discovered not through observations, but through mathematical calculations.
Uranus- the seventh planet in the solar system. Radius - 25267 km. The coldest planet has a surface temperature of -224 degrees. A year on Uranus is equal to 30,685 Earth days, that is, approximately 84 years. Day - 17 hours. Has 27 satellites.
Saturn- the sixth planet of the solar system. The radius of the planet is 57350 km. It is second in size after Jupiter. A year on Saturn is 10,759 days, which is almost 30 Earth years. A day on Saturn is almost equal to a day on Jupiter - 10.5 Earth hours. It is most similar to the Sun in the composition of chemical elements.
Has 62 satellites.
The main feature of Saturn is its rings. Their origin has not yet been established.
Jupiter- the fifth planet from the Sun. It is the largest planet in the solar system. The radius of Jupiter is 69912 km. This is as much as 19 times larger than the Earth. A year there lasts as many as 4333 Earth days, that is, almost less than 12 years. A day is about 10 Earth hours long.
Jupiter has as many as 67 satellites. The largest of them are Callisto, Ganymede, Io and Europa. Moreover, Ganymede is 8% larger than Mercury, the smallest planet in our system, and has an atmosphere.
Mars- the fourth planet of the solar system. Its radius is 3390 km, which is almost half the size of the Earth. A year on Mars is 687 Earth days. It has 2 satellites - Phobos and Deimos.
The planet's atmosphere is thin. Water found on some areas of the surface suggests that some kind of primitive life on Mars was once before or even exists now.
Venus- the second planet of the solar system. It is similar in mass and radius to the Earth. There are no satellites.
The atmosphere of Venus consists almost entirely of carbon dioxide. The percentage of carbon dioxide in the atmosphere is 96%, nitrogen - approximately 4%. Water vapor and oxygen are also present, but in very small quantities. Due to the fact that such an atmosphere creates a greenhouse effect, the temperature on the surface of the planet reaches 475 °C. A day on Venus is equal to 243 Earth days. A year on Venus is 255 days.
Pluto is a dwarf planet on the edges of the solar system, which is the dominant object in a distant system of 6 small cosmic bodies. The radius of the planet is 1195 km. Pluto's orbital period around the Sun is approximately 248 Earth years. A day on Pluto is 152 hours long. The mass of the planet is approximately 0.0025 the mass of the Earth.
It is noteworthy that Pluto was excluded from the category of planets in 2006 due to the fact that in the Kuiper belt there are objects that are larger or equal in size to Pluto, which is why, even if it is accepted as a full-fledged planet, then in this case it is necessary Add Eris to this category - which is almost the same size as Pluto.
It's hard to believe, but once upon a time Space was completely empty. There were no planets, no satellites, no stars. Where did they come from? How was the Solar System formed? These questions have troubled humanity for many centuries. This article will help give some idea of what Space is and reveal interesting facts about the planets of the Solar System.
How it all began
The Universe is the entire visible and invisible Cosmos, along with all existing cosmic bodies. Several theories have been put forward for its appearance:
3. Divine intervention. Our Universe is so unique, everything in it is thought out to the smallest detail, that it could not arise by itself. Only the Great Creator can create such a miracle. It is absolutely not a scientific theory, but it has a right to exist.
Disputes about the reasons for the true emergence of outer space continue. In fact, we have an idea of the solar system, which includes a burning star and eight planets with their satellites, galaxies, stars, comets, black holes and much more.
Amazing discoveries or interesting facts about the planets of the solar system
Outer space beckons with its mystery. Each celestial body keeps its own mystery. Thanks to astronomical discoveries, valuable information about celestial wanderers appears.
Closest to the sun is Mercury. There is an opinion that he was once a satellite of Venus. But as a result of a cosmic catastrophe, the cosmic body separated from Venus and acquired its own orbit. A year on Mercury lasts 88 days, and a day lasts 59 days.
Mercury is the only planet in the solar system where you can observe the movement of the Sun in the opposite direction. This phenomenon has a completely logical explanation. The speed of the planet's rotation around its axis is much slower than the movement in its orbit. Because of this difference in speed conditions, the effect of changing the movement of the Sun occurs.
On Mercury you can observe a fantastic phenomenon: two sunsets and sunrises. And if you move to the 0˚ and 180̊ meridians, you can witness three sunsets and sunrises per day.
Venus comes next after Mercury. It lights up in the sky during sunset on Earth, but can only be observed for a couple of hours. Because of this feature, she was nicknamed "Evening Star". It is interesting that the orbit of Venus lies inside the orbit of our planet. But it moves along it in the opposite direction, counterclockwise. A year on the planet lasts 225 days, and 1 day lasts 243 Earth days. Venus, like the Moon, has a change of phases, transforming either into a thin sickle or into a wide circle. There is an assumption that some types of terrestrial bacteria can live in the atmosphere of Venus.
Earth- truly the pearl of the solar system. Only on it there is a huge variety of life forms. People feel so comfortable on this planet and don’t even realize that it is rushing along its orbit at a speed of 108,000 km per hour.
The fourth planet from the Sun is Mars. He is accompanied by two companions. A day on this planet is equal in length to that of Earth – 24 hours. But 1 year lasts 668 days. Just like on Earth, the seasons change here. Seasons also cause changes in the appearance of the planet.
Jupiter- the largest space giant. It has many satellites (more than 60 pieces) and 5 rings. Its mass exceeds the Earth by 318 times. But, despite its impressive size, it moves quite quickly. It turns around its own axis in just 10 hours, but covers the distance around the Sun in 12 years.
The weather on Jupiter is bad - constant storms and hurricanes, accompanied by lightning. A striking representative of such weather conditions is the Great Red Spot - a vortex moving at a speed of 435 km/h.
Distinctive feature Saturn, definitely are his rings. These flat formations are made of dust and ice. The thickness of the circles ranges from 10 - 15 m to 1 km, width from 3,000 km to 300,000 km. The rings of the planet are not a single whole, but are formed in the form of thin spokes. The planet is also surrounded by more than 62 satellites.
Saturn has an incredibly high rotation rate, so much so that it is compressed at the poles. A day on the planet lasts 10 hours, a year lasts 30 years.
Uranus, like Venus, it moves around the star counterclockwise. The uniqueness of the planet lies in the fact that it “lies on its side”, its axis tilted at an angle of 98˚. There is a theory that the planet took this position after a collision with another space object.
Like Saturn, Uranus has a complex ring system consisting of a collection of inner and outer rings. Uranus has 13 of them in total. It is believed that the rings are the remains of a former satellite of Uranus that collided with the planet.
Uranus does not have a solid surface; a third of its radius, approximately 8,000 km, is a gas shell.
Neptune- the last planet of the solar system. It is surrounded by 6 dark rings. The most beautiful shade of sea green gives the planet methane, which is present in the atmosphere. Neptune completes one orbit in 164 years. But it moves quickly enough around its axis, and a day passes in
16 hours. In some places, Neptune's orbit intersects with Pluto's orbit.
Neptune has a large number of satellites. Basically, they all orbit in front of Neptune's orbit and are called internal. There are only two external satellites accompanying the planet.
You can observe it on Neptune. However, the flares are too weak and occur throughout the planet, and not exclusively at the poles, as on Earth.
Once upon a time there were 9 planets in outer space. This number included Pluto. But due to its small size, the astronomical community has classified it as a dwarf planet (asteroid).
These are the interesting facts and amazing stories about the planets of the solar system that are revealed in the process of exploring the black depths of space.
Planets of the Solar System
According to the official position of the International Astronomical Union (IAU), the organization that assigns names to astronomical objects, there are only 8 planets.
Pluto was removed from the planet category in 2006. because There are objects in the Kuiper belt that are larger/equal in size to Pluto. Therefore, even if we take it as a full-fledged celestial body, then it is necessary to add Eris to this category, which has almost the same size as Pluto.
By MAC definition, there are 8 known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
All planets are divided into two categories depending on their physical characteristics: terrestrial planets and gas giants.
Schematic representation of the location of the planets
Terrestrial planets
Mercury
The smallest planet in the solar system has a radius of only 2440 km. The period of revolution around the Sun, equated to an earthly year for ease of understanding, is 88 days, while Mercury manages to rotate around its own axis only one and a half times. Thus, his day lasts approximately 59 Earth days. For a long time it was believed that this planet always turned the same side to the Sun, since periods of its visibility from Earth were repeated with a frequency approximately equal to four Mercury days. This misconception was dispelled with the advent of the ability to use radar research and conduct continuous observations using space stations. The orbit of Mercury is one of the most unstable; not only the speed of movement and its distance from the Sun change, but also the position itself. Anyone interested can observe this effect.
Mercury in color, image from the MESSENGER spacecraft
Its proximity to the Sun is the reason why Mercury is subject to the largest temperature changes among the planets in our system. The average daytime temperature is about 350 degrees Celsius, and the nighttime temperature is -170 °C. Sodium, oxygen, helium, potassium, hydrogen and argon were detected in the atmosphere. There is a theory that it was previously a satellite of Venus, but so far this remains unproven. It does not have its own satellites.
Venus
The second planet from the Sun, the atmosphere is almost entirely composed of carbon dioxide. It is often called the Morning Star and the Evening Star, because it is the first of the stars to become visible after sunset, just as before dawn it continues to be visible even when all the other stars have disappeared from view. The percentage of carbon dioxide in the atmosphere is 96%, there is relatively little nitrogen in it - almost 4%, and water vapor and oxygen are present in very small quantities.
Venus in the UV spectrum
Such an atmosphere creates a greenhouse effect; the temperature on the surface is even higher than that of Mercury and reaches 475 °C. Considered the slowest, a Venusian day lasts 243 Earth days, which is almost equal to a year on Venus - 225 Earth days. Many call it Earth's sister because of its mass and radius, the values of which are very close to those of Earth. The radius of Venus is 6052 km (0.85% of Earth's). Like Mercury, there are no satellites.
The third planet from the Sun and the only one in our system where there is liquid water on the surface, without which life on the planet could not have developed. At least life as we know it. The radius of the Earth is 6371 km and, unlike other celestial bodies in our system, more than 70% of its surface is covered with water. The rest of the space is occupied by continents. Another feature of the Earth is the tectonic plates hidden under the planet's mantle. At the same time, they are able to move, albeit at a very low speed, which over time causes changes in the landscape. The speed of the planet moving along it is 29-30 km/sec.
Our planet from space
One revolution around its axis takes almost 24 hours, and a complete passage through the orbit lasts 365 days, which is much longer in comparison with its closest neighboring planets. The Earth's day and year are also accepted as a standard, but this is done only for the convenience of perceiving time periods on other planets. The Earth has one natural satellite - the Moon.
Mars
The fourth planet from the Sun, known for its thin atmosphere. Since 1960, Mars has been actively explored by scientists from several countries, including the USSR and the USA. Not all exploration programs have been successful, but water found at some sites suggests that primitive life exists on Mars, or existed in the past.
The brightness of this planet allows it to be seen from Earth without any instruments. Moreover, once every 15-17 years, during the Confrontation, it becomes the brightest object in the sky, eclipsing even Jupiter and Venus.
The radius is almost half that of Earth and is 3390 km, but the year is much longer - 687 days. He has 2 satellites - Phobos and Deimos .
Visual model of the solar system
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Sun
The Sun is a star that is a hot ball of hot gases at the center of our Solar System. Its influence extends far beyond the orbits of Neptune and Pluto. Without the Sun and its intense energy and heat, there would be no life on Earth. There are billions of stars like our Sun scattered throughout the Milky Way galaxy.
Mercury
Sun-scorched Mercury is only slightly larger than Earth's satellite the Moon. Like the Moon, Mercury is practically devoid of an atmosphere and cannot smooth out the traces of impact from falling meteorites, so it, like the Moon, is covered with craters. The day side of Mercury gets very hot from the Sun, while on the night side the temperature drops hundreds of degrees below zero. There is ice in the craters of Mercury, which are located at the poles. Mercury completes one revolution around the Sun every 88 days.
Venus
Venus is a world of monstrous heat (even more than on Mercury) and volcanic activity. Similar in structure and size to Earth, Venus is covered by a thick and toxic atmosphere that creates a strong greenhouse effect. This scorched world is hot enough to melt lead. Radar images through the powerful atmosphere revealed volcanoes and deformed mountains. Venus rotates in the opposite direction from the rotation of most planets.
Earth is an ocean planet. Our home, with its abundance of water and life, makes it unique in our solar system. Other planets, including several moons, also have ice deposits, atmospheres, seasons and even weather, but only on Earth did all these components come together in a way that made life possible.
Mars
Although details of the surface of Mars are difficult to see from Earth, observations through a telescope indicate that Mars has seasons and white spots at the poles. For decades, people believed that the bright and dark areas on Mars were patches of vegetation, that Mars might be a suitable place for life, and that water existed in the polar ice caps. When the Mariner 4 spacecraft arrived at Mars in 1965, many scientists were shocked to see photographs of the murky, cratered planet. Mars turned out to be a dead planet. More recent missions, however, have revealed that Mars holds many mysteries that remain to be solved.
Jupiter
Jupiter is the most massive planet in our solar system, with four large moons and many small moons. Jupiter forms a kind of miniature solar system. To become a full-fledged star, Jupiter needed to become 80 times more massive.
Saturn
Saturn is the farthest of the five planets known before the invention of the telescope. Like Jupiter, Saturn is composed primarily of hydrogen and helium. Its volume is 755 times greater than that of the Earth. Winds in its atmosphere reach speeds of 500 meters per second. These fast winds, combined with heat rising from the planet's interior, cause the yellow and golden streaks we see in the atmosphere.
Uranus
The first planet found using a telescope, Uranus was discovered in 1781 by astronomer William Herschel. The seventh planet is so far from the Sun that one revolution around the Sun takes 84 years.
Neptune
Distant Neptune rotates almost 4.5 billion kilometers from the Sun. It takes him 165 years to complete one revolution around the Sun. It is invisible to the naked eye due to its vast distance from Earth. Interestingly, its unusual elliptical orbit intersects with the orbit of the dwarf planet Pluto, which is why Pluto is inside the orbit of Neptune for about 20 years out of 248 during which it makes one revolution around the Sun.
Pluto
Tiny, cold and incredibly distant, Pluto was discovered in 1930 and was long considered the ninth planet. But after discoveries of Pluto-like worlds that were even further away, Pluto was reclassified as a dwarf planet in 2006.
Planets are giants
There are four gas giants located beyond the orbit of Mars: Jupiter, Saturn, Uranus, Neptune. They are located in the outer solar system. They are distinguished by their massiveness and gas composition.
Planets of the solar system, not to scale
Jupiter
The fifth planet from the Sun and the largest planet in our system. Its radius is 69912 km, it is 19 times larger than the Earth and only 10 times smaller than the Sun. The year on Jupiter is not the longest in the solar system, lasting 4333 Earth days (less than 12 years). His own day has a duration of about 10 Earth hours. The exact composition of the planet's surface has not yet been determined, but it is known that krypton, argon and xenon are present on Jupiter in much larger quantities than on the Sun.
There is an opinion that one of the four gas giants is actually a failed star. This theory is also supported by the largest number of satellites, of which Jupiter has many - as many as 67. To imagine their behavior in the planet’s orbit, you need a fairly accurate and clear model of the solar system. The largest of them are Callisto, Ganymede, Io and Europa. Moreover, Ganymede is the largest satellite of the planets in the entire solar system, its radius is 2634 km, which is 8% greater than the size of Mercury, the smallest planet in our system. Io has the distinction of being one of only three moons with an atmosphere.
Saturn
The second largest planet and the sixth in the solar system. In comparison with other planets, it is most similar to the Sun in the composition of chemical elements. The radius of the surface is 57,350 km, the year is 10,759 days (almost 30 Earth years). A day here lasts a little longer than on Jupiter - 10.5 Earth hours. In terms of the number of satellites, it is not much behind its neighbor - 62 versus 67. The largest satellite of Saturn is Titan, just like Io, which is distinguished by the presence of an atmosphere. Slightly smaller in size, but no less famous are Enceladus, Rhea, Dione, Tethys, Iapetus and Mimas. It is these satellites that are the objects for the most frequent observation, and therefore we can say that they are the most studied in comparison with the others.
For a long time, the rings on Saturn were considered a unique phenomenon unique to it. Only recently it was established that all gas giants have rings, but in others they are not so clearly visible. Their origin has not yet been established, although there are several hypotheses about how they appeared. In addition, it was recently discovered that Rhea, one of the satellites of the sixth planet, also has some kind of rings.
> Planets
Explore everything planets of the solar system in order and study the names, new scientific facts and interesting features of the surrounding worlds with photos and videos.
The solar system is home to 8 planets: Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus and Neptune. The first 4 belong to the inner solar system and are considered terrestrial planets. Jupiter and Saturn are the large planets of the solar system and representatives of the gas giants (huge and filled with hydrogen and helium), and Uranus and Neptune are ice giants (large and represented by heavier elements).
Previously, Pluto was considered the ninth planet, but since 2006 it has become a dwarf planet. This dwarf planet was first discovered by Clyde Tomb. It is now one of the largest objects in the Kuiper Belt, a collection of icy bodies on the outer edge of our system. Pluto lost its planetary status after the IAU (International Astronomical Union) revised the concept itself.
According to the IAU decision, a solar system planet is a body that performs an orbital passage around the Sun, endowed with sufficient mass to form into a sphere and clear the area around it of foreign objects. Pluto failed to meet the latter requirement, which is why it became a dwarf planet. Other similar objects include Ceres, Makemake, Haumea and Eris.
With a small atmosphere, harsh surface features and 5 moons, Pluto is considered the most complex dwarf planet and one of the most amazing planets in our solar system.
But scientists have not given up hope of finding the mysterious Planet Nine, after they announced in 2016 a hypothetical object that exerts its gravity on bodies in the Kuiper Belt. In terms of parameters, it is 10 times the mass of the Earth and 5000 times more massive than Pluto. Below is a list of planets of the solar system with photos, names, descriptions, detailed characteristics and interesting facts for children and adults.
Variety of planets
Astrophysicist Sergei Popov about gas and ice giants, double star systems and single planets:
Hot planetary coronas
Astronomer Valery Shematovich on the study of gaseous shells of planets, hot particles in the atmosphere and discoveries on Titan:
Planet | Diameter relative to the Earth | Mass, relative to Earth | Orbital radius, a. e. | Orbital period, Earth years | Day, relative to Earth |
Density, kg/m³ | Satellites |
---|---|---|---|---|---|---|---|
0,382 | 0,06 | 0,38 | 0,241 | 58,6 | 5427 | No | |
0,949 | 0,82 | 0,72 | 0,615 | 243 | 5243 | No | |
1,0 | 1,0 | 1,0 | 1,0 | 1,0 | 5515 | 1 | |
0,53 | 0,11 | 1,52 | 1,88 | 1,03 | 3933 | 2 | |
0,074 | 0,000013 | 2,76 | 4,6 | 0,46 | ~2000 | No | |
11,2 | 318 | 5,20 | 11,86 | 0,414 | 1326 | 67 | |
9,41 | 95 | 9,54 | 29,46 | 0,426 | 687 | 62 | |
3,98 | 14,6 | 19,22 | 84,01 | 0,718 | 1270 | 27 | |
3,81 | 17,2 | 30,06 | 164,79 | 0,671 | 1638 | 14 | |
0,098 | 0,0017 | 39,2 | 248,09 | 6,3 | 2203 | 5 | |
0,032 | 0,00066 | 42,1 | 281,1 | 0,03 | ~1900 | 2 | |
0,033 | 0,00065 | 45,2 | 306,28 | 1,9 | ~1700 | No | |
0,1 | 0,0019 | 68,03 | 561,34 | 1,1 | ~2400 | 1 |
Terrestrial planets of the solar system
The first 4 planets from the Sun are called terrestrial planets because their surface is rocky. Pluto also has a solid surface layer (frozen), but it is classified as a dwarf planet.
Gas giant planets of the solar system
There are 4 gas giants living in the outer solar system, as they are quite huge and gaseous. But Uranus and Neptune are different because they have more ice. That's why they are also called ice giants. However, all gas giants have one thing in common: they are all made of hydrogen and helium.
The IAU has put forward a definition of a planet:
- The object must be orbiting the Sun;
- Have sufficient mass to take the shape of a ball;
- Clear your orbital path of foreign objects;
Pluto could not meet the latter requirement, since it shares its orbital path with a huge number of Kuiper Belt bodies. But not everyone agreed with the definition. However, dwarf planets such as Eris, Haumea and Makemake appeared on the scene.
Ceres also lives between Mars and Jupiter. It was noticed in 1801 and considered a planet. Some still consider it the 10th planet of the solar system.
Dwarf planets of the solar system
Formation of planetary systems
Astronomer Dmitry Vibe about rocky planets and giant planets, the diversity of planetary systems and hot Jupiters:
Planets of the Solar System in order
The following describes the characteristics of the 8 main planets of the Solar System in order from the Sun:
The first planet from the Sun is Mercury
Mercury is the first planet from the Sun. Rotates in an elliptical orbit at a distance of 46-70 million km from the Sun. It takes 88 days for one orbital flight, and 59 days for an axial flight. Due to its slow rotation, a day spans 176 days. The axial tilt is extremely small.
With a diameter of 4887 km, the first planet from the Sun reaches 5% of the Earth's mass. Surface gravity is 1/3 of Earth's. The planet is practically devoid of an atmospheric layer, so it is hot during the day and freezes at night. The temperature ranges between +430°C and -180°C.
There is a crater surface and an iron core. But its magnetic field is inferior to that of the earth. Initially, radar indicated the presence of water ice at the poles. The Messenger apparatus confirmed the assumptions and found deposits at the bottom of craters, which are always immersed in shadow.
The first planet from the Sun is located close to the star, so it can be seen before dawn and just after sunset.
- Title: Messenger of the gods in the Roman pantheon.
- Diameter: 4878 km.
- Orbit: 88 days.
- Length of day: 58.6 days.
The second planet from the Sun is Venus
Venus is the second planet from the Sun. Travels in an almost circular orbit at a distance of 108 million km. It comes closest to Earth and can reduce the distance to 40 million km.
The orbital path takes 225 days, and the axial rotation (clockwise) lasts 243 days. A day spans 117 Earth days. The axial tilt is 3 degrees.
In diameter (12,100 km), the second planet from the Sun is almost identical to the Earth’s and reaches 80% of the Earth’s mass. The gravity indicator is 90% of Earth's. The planet has a dense atmospheric layer, where the pressure is 90 times higher than Earth's. The atmosphere is filled with carbon dioxide with thick sulfur clouds, creating a powerful greenhouse effect. It is because of this that the surface warms up by 460°C (the hottest planet in the system).
The surface of the second planet from the Sun is hidden from direct observation, but scientists were able to create a map using radar. Covered by large volcanic plains with two huge continents, mountains and valleys. There are also impact craters. A weak magnetic field is observed.
- Discovery: The ancients saw without the use of tools.
- Name: Roman goddess responsible for love and beauty.
- Diameter: 12104 km.
- Orbit: 225 days.
- Day length: 241 days.
The third planet from the Sun is Earth
Earth is the third planet from the Sun. It is the largest and densest of the inner planets. The orbital path is 150 million km away from the Sun. It has a single companion and developed life.
The orbital flyby takes 365.25 days, and the axial rotation takes 23 hours, 56 minutes and 4 seconds. The length of the day is 24 hours. The axial tilt is 23.4 degrees, and the diameter is 12742 km.
The third planet from the Sun was formed 4.54 billion years ago and for most of its existence the Moon was nearby. It is believed that the satellite appeared after a huge object crashed into the Earth and tore material into orbit. It is the Moon that stabilizes the Earth's axial tilt and acts as the source of the formation of tides.
The satellite's diameter covers 3,747 km (27% of Earth's) and is located at a distance of 362,000-405,000 km. Experiencing planetary gravitational influence, due to which it slowed down its axial rotation and fell into a gravitational block (therefore, one side is turned towards the Earth).
The planet is protected from stellar radiation by a powerful magnetic field formed by the active core (molten iron).
- Diameter: 12760 km.
- Orbit: 365.24 days.
- Day length: 23 hours and 56 minutes.
The fourth planet from the Sun is Mars
Mars is the fourth planet from the Sun. The Red Planet moves along an eccentric orbital path - 230 million km. One flight around the Sun takes 686 days, and an axial revolution takes 24 hours and 37 minutes. It is located at an inclination of 25.1 degrees, and the day lasts 24 hours and 39 minutes. Its inclination resembles that of the Earth, which is why it has seasons.
The diameter of the fourth planet from the Sun (6792 km) is half that of Earth, and its mass reaches 1/10 of Earth’s. Gravity indicator – 37%.
Mars has no protection as a magnetic field, so the original atmosphere was destroyed by the solar wind. The devices recorded the outflow of atoms into space. As a result, the pressure reaches 1% of the earth's, and the thin atmospheric layer is represented by 95% carbon dioxide.
The fourth planet from the Sun is extremely frosty, with temperatures dropping to -87°C in winter and rising to -5°C in summer. This is a dusty place with giant storms that can cover the entire surface.
- Discovery: The ancients saw without the use of tools.
- Name: Roman god of war.
- Diameter: 6787 km.
- Orbit: 687 days.
- Day length: 24 hours and 37 minutes.
The fifth planet from the Sun is Jupiter
Jupiter is the fifth planet from the Sun. In addition, this is the largest planet in the system, which is 2.5 times more massive than all the planets and covers 1/1000 of the solar mass.
It is distant from the Sun by 780 million km and spends 12 years on its orbital path. Filled with hydrogen (75%) and helium (24%) and may have a rocky core immersed in liquid metallic hydrogen with a diameter of 110,000 km. The total planetary diameter is 142984 km.
In the upper layer of the atmosphere there are 50-kilometer clouds, represented by ammonia crystals. They are in bands moving at different speeds and latitudes. The Great Red Spot, a large-scale storm, seems remarkable.
The fifth planet from the Sun spends 10 hours on its axial rotation. This is a rapid speed, which means the equatorial diameter is 9000 km larger than the polar one.
- Discovery: The ancients saw without the use of tools.
- Name: the main god in the Roman pantheon.
- Diameter: 139822 km.
- Orbit: 11.9 years.
- Length of day: 9.8 hours.
The sixth planet from the Sun is Saturn
Saturn is the sixth planet from the Sun. Saturn is in 2nd position in terms of scale in the system, exceeding the Earth's radius by 9 times (57,000 km) and 95 times more massive.
It is distant from the Sun by 1400 million km and spends 29 years on its orbital flight. Filled with hydrogen (96%) and helium (3%). May have a rocky core in liquid metallic hydrogen with a diameter of 56,000 km. The upper layers are represented by liquid water, hydrogen, ammonium hydrosulfide and helium.
The core is heated to 11,700°C and produces more heat than the planet receives from the Sun. The higher we rise, the lower the degree drops. At the top, the temperature is maintained at -180°C and 0°C at a depth of 350 km.
The cloud layers of the sixth planet from the Sun resemble the picture of Jupiter, but they are fainter and wider. There is also the Great White Spot, a brief periodic storm. It spends 10 hours and 39 minutes on an axial rotation, but it is difficult to give an exact figure, since there are no fixed surface features.
- Discovery: The ancients saw without the use of tools.
- Name: god of the economy in the Roman pantheon.
- Diameter: 120500 km.
- Orbit: 29.5 days.
- Length of day: 10.5 hours.
The seventh planet from the Sun is Uranus
Uranus is the seventh planet from the Sun. Uranus is a representative of the ice giants and is the 3rd largest in the system. Its diameter (50,000 km) is 4 times greater than that of Earth and 14 times more massive.
It is distant by 2900 million km and spends 84 years on its orbital path. What’s surprising is that the planet’s axial tilt (97 degrees) literally rotates on its side.
It is believed that there is a small rocky core around which a mantle of water, ammonia and methane is concentrated. This is followed by a hydrogen, helium and methane atmosphere. The seventh planet from the Sun also stands out in that it does not radiate more internal heat, so the temperature mark drops to -224°C (the coldest planet).
- Discovery: In 1781, noticed by William Herschel.
- Name: personification of the sky.
- Diameter: 51120 km.
- Orbit: 84 years.
- Duration of the day: 18 hours.
Neptune is the eighth planet from the Sun. Neptune has been considered the official last planet in the solar system since 2006. The diameter is 49,000 km, and its massiveness is 17 times greater than that of Earth.
It is distant by 4500 million km and spends 165 years on an orbital flight. Due to its remoteness, the planet receives only 1% of solar radiation (compared to Earth). The axial tilt is 28 degrees, and the rotation takes 16 hours.
The meteorology of the eighth planet from the Sun is more pronounced than that of Uranus, so powerful storm activity can be seen at the poles in the form of dark spots. The wind accelerates to 600 m/s, and the temperature drops to -220°C. The core heats up to 5200°C.
- Discovery: 1846
- Name: Roman god of water.
- Diameter: 49530 km.
- Orbit: 165 years.
- Duration of the day: 19 hours.
This is a small world, smaller in size than Earth's satellite. The orbit intersects with Neptune in 1979-1999. it could be considered the 8th planet in terms of distance from the Sun. Pluto will remain beyond Neptune's orbit for more than two hundred years. The orbital path is inclined to the system plane at 17.1 degrees. Frosty World visited New Horizons in 2015.
- Discovery: 1930 - Clyde Tombaugh.
- Name: Roman god of the underworld.
- Diameter: 2301 km.
- Orbit: 248 years.
- Length of day: 6.4 days.
Planet Nine is a hypothetical object residing in the outer system. Its gravity should explain the behavior of trans-Neptunian objects.