What does gas giant mean. Solar system. Age of planet earth

1977

Gas giants are called planets, the bulk of which consists of gases of various types. These gases are predominantly hydrogen and helium. To a lesser extent, the presence of ammonia and methane, and sometimes nitrogen, is possible. Such planets are usually characterized by low temperatures and high pressure in the atmosphere.

The main features of the gas giants:

1. They have a low density. Thus, they do not have a solid surface in the usual sense for us.
2. They have an extremely short period of daily rotation. It is approximately from 9 to 17 hours, which is very small by earthly standards.
3. Due to the rapid rotation, as a rule, they are compressed or flattened in the region of the poles.
4. They scatter the sun's rays well.

The structure of gas giants

The structure of gas planets consists of several layers:

• gaseous (represented in the form of clouds);
• liquid gas arising due to high pressure;
• metallic gas (an electromagnetic field arises here);
• a small core, which can be metal or stone.

Gas planets are characterized by the presence of strong winds in their atmospheres, reaching thousands of kilometers. As well as stable giant whirlwinds that have existed for more than one hundred years.

According to modern data, most of the planets outside our solar system, that is, exoplanets, are gas. There are about a hundred billion of them in our galaxy now.

Gas giants of the solar system

All the planets of our solar system are usually divided into two parts: external and internal. The gas giants are represented by a group known in science as the "outer planets". It includes Neptune, Uranus, Saturn and Jupiter. They are further from the Sun than the rest - the inner planets and are separated from them by a belt of asteroids.

Outer planets have a set of common distinguishing features:

1. Considerable distance from the Sun.
2. The presence of strong magnetic fields.
3. Large size and weight.
4. The presence of many satellites around the planet.
5. Low temperatures.
6. The presence of ring systems encircling the planet.

The largest of the outer planets is Jupiter. It is the fifth in distance from the Sun. It has an atmosphere composed primarily of hydrogen and eleven percent helium. The presence of sulfur and phosphorus in it gives a beautiful orange color to the appearance of the planet. In the lower layers is an ocean filled with liquid hydrogen.

There are classic signs of gas planets here: strong winds and long (up to three hundred years of existence) whirlwinds. The most gigantic of the latter is the Great Red Spot. Its dimensions are several times larger than the earth.

The planet has a powerful magnetic field of 650 million kilometers. Twenty-eight satellites rotate in its zone.

The next gas giant of the outer system is Saturn. The planet is the second largest in our solar system. Its rotation time is very short - just over 10 hours. In size, it is slightly inferior to Jupiter. But by weight - three times.

The composition of Saturn includes mainly hydrogen, helium, ammonia, methane and the remains of water are present to a small extent.

The famous ring of Saturn, surrounding it at the equator, is not a single whole. Its outer layers revolve around the planet at a much slower speed than the inner ones. In their structure, they consist of the smallest particles of ice with the addition of silicate dust. In width, they can reach eighty thousand kilometers. The thickness of the rings is much less - no more than one kilometer.

The length of the year on Saturn is 29.5 times longer than the earth. During the annual cycle, the appearance of the rings of a celestial body from the Earth varies greatly.

The equinox period is characterized by the termination of the possibility of their observation. That is, they practically cease to be visible from our planet, with the exception of a small line. Thereafter, over a period of seven years, the rings become more and more visible in width and reach their maximum visual size when the solstice occurs. Then the cycle repeats.

Saturn has sixty-two moons. Their composition is represented by rocks and ice, and their sizes are usually small. One of its satellites, Titan, which received its name for the maximum size compared to others, has a dense atmosphere, consisting mainly of nitrogen with the addition of methane. Scientists suggest that such conditions could exist on Earth during the period of the appearance of life on it.

The planet next to Saturn is Uranus. Discovered in the 17th century, it is the fourth largest in the solar system.

A year on Uranus is 84 times longer than an Earth year, and it rotates around its axis in just seventeen hours. In the composition of Uranus, unlike most other planets except Neptune, scientists have not found metallic hydrogen. However, a large percentage of ice was found there. Therefore, the planet, like Neptune, was classified as an ice giant.

In its hydrogen-helium atmosphere, impurities of methane, ammonia and hydrogen were found.

Uranus is the coldest planet in the solar system. With a temperature of 224 degrees Celsius, it is completely uninhabitable.

The presence of weakly expressed rings on Uranus is undoubted. At the same time, the outer ring formations have a brighter color.

A feature of Uranus is its property of rotation in a horizontal position, as if lying on its "side". Twenty-seven satellites of the planet are named after the heroes of the works of W. Shakespeare and A. Pope.

The last, and smallest, of the outer gas giants is Neptune. Not visible from Earth, it has a unique history of discovery, as it was first discovered not visually, but with the help of mathematical calculations. The reason for this was changes in the orbit of Uranus and the assumption that they are caused by the influence of the gravity of an unknown planet.

Neptune is similar in composition to Uranus. This led scientists to attribute it to the ice giants. The surface of the planet is an ocean of water and liquefied gases. One year on the planet corresponds to approximately 165 Earth years. A day lasts about 16 hours.

Due to the internal energy source of Neptune, the strongest winds in the solar system arise on it. They can reach 2100 kilometers per hour. The atmosphere of the planet is characterized by persistent storms that last for several months.

On Neptune, faintly expressed rings with a reddish tint were discovered. It is assumed that it is given by the presence in their composition, people with ice and silicate, carbon.

Neptune has the strongest magnetic field, with a length of 650 thousand kilometers. But, unlike the Earth, its orbit is deviated from the axis of rotation of the planet itself by 47 degrees.

Of the fourteen moons of Neptune, Triton is the largest.

Currently, there is also a theory among scientists that in our solar system there was another planet that was a gas giant. But under the influence of Jupiter's gravity, she had to be out of the region of attraction of the Sun.

largest gas giant

At the beginning of the 21st century, the largest planet in the Universe was discovered, which is also a gas giant. She was given the name TrES-4. It is located in the constellation Hercules, at a distance of 1600 light years from our planet. The celestial body is twenty times larger than the Earth. It is 1.7 times larger than Jupiter in diameter, but only three times as massive. A day on TrES-4 is equal to three and a half Earth days.

Due to the proximity to the mother star, the temperature on the planet is extremely high and reaches approximately 1260 degrees. Therefore, and also because of the small mass, it is constantly expanding. TrES-4 cannot contain the atmosphere. Part of it is constantly evaporating, transforming into a tail, like those that accompany a comet.

Any large planet can be classified as a giant. Such planets are mostly composed of substances with low boiling points, such as ice and gases, although there are giant planets like Earth. The solar system's giant planets, also referred to as the outer planets, include Jupiter, Neptune, Uranus, and Saturn. The phrase gas giant was first used in 1952 by James Blish, a science fiction writer.

The four largest planets in the solar system are:

Jupiter

The mass of Jupiter is 2.5 times heavier than the total mass of the others and is one thousandth of the mass of the Sun. Jupiter is a gas giant, mostly composed of hydrogen, and also a quarter of its mass of helium. The rapid rotation has affected the shape of the planet, making it oblate spheroidal. Jupiter's diameter at the equator is 142,984 km. Jupiter has intrigued the minds of astronomers since ancient times, and the Romans even gave it a name in honor of their chief deity, Jupiter. The planet has at least 69 moons (satellites), and the largest of them - Ganymede is considered the largest in the solar system and exceeds Mercury in diameter.

Saturn

Saturn, like Jupiter, is a gas giant that is also formed from helium and hydrogen. It is distinguished by its ring system, which includes 9 continuous primary rings in addition to 3 discontinuous arches. The planet has at least 62 moons, 53 of which are officially named. This figure excludes the hundreds of lunar zones that make up the rings. The largest of Saturn's moons is Titan, which is the second largest moon in our system. Saturn is about 30% less dense than water. Jupiter and Saturn together make up 92% of the total mass of the planets in the solar system.

Uranus

Uranus is classified as an ice giant, and although it is dominated by hydrogen and helium, it has more "ice" including methane, water and ammonia. Uranus was named after the Greek god of the sky named Ouranos. The planet has 27 satellites, a magnetosphere and a ring system. The temperature minimum of Uranus is estimated at -223 degrees Celsius, which makes its atmosphere . Uranus makes a complete revolution around the Sun every 84 years, and the average distance to a star is 20 astronomical units. The mass of Uranus is just over fourteen and a half times the mass of the Earth.

Neptune

The mass of Neptune is seventeen times that of the Earth. Neptune is recognized as the only planet in the solar system discovered through mathematical calculations, rather than empirical observations. Johann Galle became the first person to identify a planet through a telescope on September 23, 1846, and he relied on Urban Le Verrier's predictions. The largest satellite of Neptune - Triton was discovered just two and a half weeks after the planet itself, although the remaining 13 satellites were identified using a telescope only in the 20th century. The significant distance from Earth to Neptune makes it very small, making it difficult to study the planet through a telescope. Advanced modern telescopes with adaptive optics have made it easier to obtain additional information from afar. Neptune's atmosphere has visible and active weather patterns, while temperatures at the planet's center are estimated at 5,100 degrees Celsius.

1978

Gas giants are called planets, the bulk of which consists of gases of various types. These gases are predominantly hydrogen and helium. To a lesser extent, the presence of ammonia and methane, and sometimes nitrogen, is possible. Such planets are usually characterized by low temperatures and high pressure in the atmosphere.

The main features of the gas giants:

1. They have a low density. Thus, they do not have a solid surface in the usual sense for us.
2. They have an extremely short period of daily rotation. It is approximately from 9 to 17 hours, which is very small by earthly standards.
3. Due to the rapid rotation, as a rule, they are compressed or flattened in the region of the poles.
4. They scatter the sun's rays well.

The structure of gas giants

The structure of gas planets consists of several layers:

• gaseous (represented in the form of clouds);
• liquid gas arising due to high pressure;
• metallic gas (an electromagnetic field arises here);
• a small core, which can be metal or stone.

Gas planets are characterized by the presence of strong winds in their atmospheres, reaching thousands of kilometers. As well as stable giant whirlwinds that have existed for more than one hundred years.

According to modern data, most of the planets outside our solar system, that is, exoplanets, are gas. There are about a hundred billion of them in our galaxy now.

Gas giants of the solar system

All the planets of our solar system are usually divided into two parts: external and internal. The gas giants are represented by a group known in science as the "outer planets". It includes Neptune, Uranus, Saturn and Jupiter. They are further from the Sun than the rest - the inner planets and are separated from them by a belt of asteroids.

Outer planets have a set of common distinguishing features:

1. Considerable distance from the Sun.
2. The presence of strong magnetic fields.
3. Large size and weight.
4. The presence of many satellites around the planet.
5. Low temperatures.
6. The presence of ring systems encircling the planet.

The largest of the outer planets is Jupiter. It is the fifth in distance from the Sun. It has an atmosphere composed primarily of hydrogen and eleven percent helium. The presence of sulfur and phosphorus in it gives a beautiful orange color to the appearance of the planet. In the lower layers is an ocean filled with liquid hydrogen.

There are classic signs of gas planets here: strong winds and long (up to three hundred years of existence) whirlwinds. The most gigantic of the latter is the Great Red Spot. Its dimensions are several times larger than the earth.

The planet has a powerful magnetic field of 650 million kilometers. Twenty-eight satellites rotate in its zone.

The next gas giant of the outer system is Saturn. The planet is the second largest in our solar system. Its rotation time is very short - just over 10 hours. In size, it is slightly inferior to Jupiter. But by weight - three times.

The composition of Saturn includes mainly hydrogen, helium, ammonia, methane and the remains of water are present to a small extent.

The famous ring of Saturn, surrounding it at the equator, is not a single whole. Its outer layers revolve around the planet at a much slower speed than the inner ones. In their structure, they consist of the smallest particles of ice with the addition of silicate dust. In width, they can reach eighty thousand kilometers. The thickness of the rings is much less - no more than one kilometer.

The length of the year on Saturn is 29.5 times longer than the earth. During the annual cycle, the appearance of the rings of a celestial body from the Earth varies greatly.

The equinox period is characterized by the termination of the possibility of their observation. That is, they practically cease to be visible from our planet, with the exception of a small line. Thereafter, over a period of seven years, the rings become more and more visible in width and reach their maximum visual size when the solstice occurs. Then the cycle repeats.

Saturn has sixty-two moons. Their composition is represented by rocks and ice, and their sizes are usually small. One of its satellites, Titan, which received its name for the maximum size compared to others, has a dense atmosphere, consisting mainly of nitrogen with the addition of methane. Scientists suggest that such conditions could exist on Earth during the period of the appearance of life on it.

The planet next to Saturn is Uranus. Discovered in the 17th century, it is the fourth largest in the solar system.

A year on Uranus is 84 times longer than an Earth year, and it rotates around its axis in just seventeen hours. In the composition of Uranus, unlike most other planets except Neptune, scientists have not found metallic hydrogen. However, a large percentage of ice was found there. Therefore, the planet, like Neptune, was classified as an ice giant.

In its hydrogen-helium atmosphere, impurities of methane, ammonia and hydrogen were found.

Uranus is the coldest planet in the solar system. With a temperature of 224 degrees Celsius, it is completely uninhabitable.

The presence of weakly expressed rings on Uranus is undoubted. At the same time, the outer ring formations have a brighter color.

A feature of Uranus is its property of rotation in a horizontal position, as if lying on its "side". Twenty-seven satellites of the planet are named after the heroes of the works of W. Shakespeare and A. Pope.

The last, and smallest, of the outer gas giants is Neptune. Not visible from Earth, it has a unique history of discovery, as it was first discovered not visually, but with the help of mathematical calculations. The reason for this was changes in the orbit of Uranus and the assumption that they are caused by the influence of the gravity of an unknown planet.

Neptune is similar in composition to Uranus. This led scientists to attribute it to the ice giants. The surface of the planet is an ocean of water and liquefied gases. One year on the planet corresponds to approximately 165 Earth years. A day lasts about 16 hours.

Due to the internal energy source of Neptune, the strongest winds in the solar system arise on it. They can reach 2100 kilometers per hour. The atmosphere of the planet is characterized by persistent storms that last for several months.

On Neptune, faintly expressed rings with a reddish tint were discovered. It is assumed that it is given by the presence in their composition, people with ice and silicate, carbon.

Neptune has the strongest magnetic field, with a length of 650 thousand kilometers. But, unlike the Earth, its orbit is deviated from the axis of rotation of the planet itself by 47 degrees.

Of the fourteen moons of Neptune, Triton is the largest.

Currently, there is also a theory among scientists that in our solar system there was another planet that was a gas giant. But under the influence of Jupiter's gravity, she had to be out of the region of attraction of the Sun.

largest gas giant

At the beginning of the 21st century, the largest planet in the Universe was discovered, which is also a gas giant. She was given the name TrES-4. It is located in the constellation Hercules, at a distance of 1600 light years from our planet. The celestial body is twenty times larger than the Earth. It is 1.7 times larger than Jupiter in diameter, but only three times as massive. A day on TrES-4 is equal to three and a half Earth days.

Due to the proximity to the mother star, the temperature on the planet is extremely high and reaches approximately 1260 degrees. Therefore, and also because of the small mass, it is constantly expanding. TrES-4 cannot contain the atmosphere. Part of it is constantly evaporating, transforming into a tail, like those that accompany a comet.

By earthly standards, the solar system has not just large, but vast and boundless spaces. In order not to scare yourself with crazy numbers in kilometers, experts came up with such a unit of measurement for the vast and boundless expanses of space as astronomical unit. One such a. e. is equal to 149.6 million km - this is the average distance of the Earth from the Sun.

A general idea of ​​​​the size of the entire solar system gives the distance between the Sun and the planet Pluto. It is neither more nor less than thirty-nine astronomical units, and this is under the condition that the small planet is located at the closest point in the orbit to the Sun - perihelion. If Pluto, moving along its orbit, falls into aphelion - the farthest point of the orbit, then the distance increases to forty-nine astronomical units.

From this it is easy to calculate that light, which has a speed of 299,792 km/s, reaches the Earth in eight minutes. This is the approximate time that an office worker spends having a pleasant conversation with colleagues over a cup of coffee. They took a coffee pot in their hands - a gamma-quantum particle separated from the Sun and rushed towards the Earth. They put an empty cup on the table, brushed the crumbs from the eaten confectionery onto the floor - the messenger of the yellow star hit the table set and, reflected, merged with many other reflected particles. The magnitude of the brightness of such reflected sunlight is called albedo.

For reference, it should be noted that light reaches Pluto in six hours. If we take intergalactic spaces, then there are completely different measurement criteria. Huge distances, say, to our respected neighbor Andromeda, are already measured in light years and parsecs.

All nine planets coexist perfectly with each other. This can be seen by every curious pilgrim who happened to be at the North Pole, and besides, he took a telescope with him. Shivering from the cold and admiring the beauty of the starry sky, he can easily find that the planets of the solar system move counterclockwise, and even lie approximately in the same plane. The plane of the orbit of the planet Earth is always taken as the basis, which coincides with the section of the celestial sphere and is called the plane of the ecliptic.

Further observations will delight the traveler's eye and bring peace to his soul: all nine cosmic bodies rotate in strictly allotted spaces in elliptical orbits, so they cannot crash into each other. True, it will be difficult for our newly minted astronomer to notice the main thing: the planets are divided into two groups, and between them there is an asteroid belt.

The first group includes four planets located closest to the Sun. These are Mercury, Venus, Earth and Mars. They have many features in common: approximately the same density (average 4.5 g/cm³), small size, slow rotation around their axis, and a small number of natural satellites. Only the Earth has them - the Moon and Mars - Phobos and Deimos. These four planets are called terrestrial planets.

But beyond the asteroid belt, the picture is quite different. The other four planets rule there: Jupiter, Saturn, Uranus and Neptune. They are also similar in density (on average 1.2 g/cm³), are huge, rotate rapidly around their axis and are surrounded by a large number of satellites. In addition, they lack a solid surface, and their atmospheres are saturated with hydrogen and helium. These four planets are called gas giants.

A small and neat Pluto stands apart, which in its characteristics is similar to the planets of the first group. True, his status has recently changed. Now it is called a dwarf planet: the International Astronomical Union decided so. To be honest, this verdict did not receive unanimous support among scientists, and many still consider Pluto to be the ninth planet in the solar system.

The protostar continued to shrink, its temperature increased. Finally, it reached millions of kelvins in the center and provoked the start of thermonuclear reactions of hydrogen combustion. Helium began to be released, and the protostar passed into a new quality - it became an ordinary star (the Sun). All these cosmic transformations stretched over more than one million years in time.

Next came the formation of planets. The dust layer was characterized by hydrodynamic instability and was soon replaced by dust seals. They collided with each other, compressed - they were replaced by solid bodies of small size. These new formations were combined into larger ones. It was they who became the gravitational centers for the formation of planets from the substance of the protoplanetary disk.

The system strove for stability, and, in the end, in the outer regions of the disk, the gravitational centers formed nine planets, rotating in the same plane and in the same direction. It took about four million years. The initial formation of the solar system ended there.

Its further evolution is characterized by a change in the orbits and a change in the order of the planets, the emergence of satellites around them. This process continues now, once again proving that there are no frozen forms in the Cosmos that are not subject to gravitational interactions. They are the primary cause of all long-term changes in previous states, both in the solar system itself and in larger interstellar and intergalactic formations.

From all of the above, it can be seen that over the past centuries, humanity has not wasted time in vain and has created a fairly coherent theory covering all aspects of the solar system. But this is only at first glance. The true state of things is such that a huge number of questions, ambiguities and frank secrets have accumulated today. The answers to them are very contradictory and vague, and the truth is unclear and foggy.

Age of the solar system

One of the main mysteries age of the solar system. The official version has already been mentioned, which calls the time interval 4.6–5 billion years. But it explains little if it is considered from the point of view of the methodology for calculating the amount of helium, which is the result of thermonuclear reactions and is currently present on the Sun.

The fact is that the estimate of the amount of this inert gas is not an obvious quantity. Someone claims that it contains 34% of the total solar mass, and someone calls 27%. The run is seven percent. Accordingly, the time interval can vary from 5 to 6.5 billion years, and even then only from the moment when the protostar turned into the Sun.

At present, there is not even a clear idea of ​​the thermonuclear reactions that take place in the bowels of a yellow dwarf. There are two proposed cycles for the conversion of hydrogen into helium - a proton (hydrogen) and carbon (Bethe cycle).

Experts are more inclined towards the first cycle, which includes three reactions: a deuterium nucleus is formed from a hydrogen nucleus, then a helium isotope nucleus with an atomic mass of three is formed from a deuterium nucleus, and the process ends with a stable helium isotope with an atomic mass of four.

Age of planet earth

What is really more or less clear and not subject to criticism is the age of the planet Earth and its moon. Here, the concept of radioactivity is taken as a basis. It is understood as the transformation of atomic nuclei into other nuclei, accompanied by the emission of various particles and electromagnetic radiation.

In this case, the uranium atom is taken as the basis. It is unstable, emits energy and transforms over time into a lead atom, which is a stable element. Provided that the rate of nuclear decay is absolutely constant, it is easy to calculate the time period during which one element is replaced by another.

Any mass of uranium (isotope) has a certain number of atoms. Replacing half of the uranium atoms with a similar number of lead atoms occurs in 4.5 billion years - the half-life. The complete transformation of uranium into lead is, respectively, 9 billion years.

The oldest mineral on Earth was found in Australia, its age was determined at 4.2 billion years. The meteorites that fall on the blue planet are also far from young - they are usually 4.5-4.6 billion years old. Thanks to modern achievements of science (the American expedition "Apollo", the Soviet automatic interplanetary station "Luna"), samples of lunar soil were delivered to Earth. He was not the first freshness. His years fluctuate in a fork from 4 to 4.5 billion years.

Many immediately seized on these figures, categorically declaring that the existence of the entire solar system also lies in this time interval. Nobody argues - the Earth and the Moon live according to the same laws as other cosmic bodies. But who will give an absolute guarantee that in the near future a mineral will not be found in the bowels of our planet, whose age will be, for example, 8 billion years, or a sample of an equally venerable age will be delivered from the Moon. It is also not known what the soil of other planets, colleagues of the old Earth, is like.

In short, the question of the maturity of the solar system is still open. Most likely in the near future a clear and precise answer will not be found. But the truth is always on the side of the stubborn and inquisitive. Some time will pass, humanity will master the stock of new knowledge, and then it will itself be surprised how it could not see the answers that practically lay on the surface before..

The article was written by ridar-shakin

Sources: Publication "Planets of the Solar System"

Hi friends. There are 4 smaller inner planets in our solar system: Mercury, Venus, Earth and Mars, which are made up mostly of silicates and metals. The 4 outer planets are more massive. Jupiter, Saturn, Uranus and Neptune are gas giants that contain hydrogen, helium, methane and carbon monoxide. All 8 planets have almost circular orbits and are located within an almost flat disk - the plane of the ecliptic. I wonder what would happen if, for example, Saturn began to slowly descend from its orbit and approach the Earth? This frame shows how the second largest planet in our solar system crosses the orbit of Mars. Already at this distance, Saturn becomes the brightest object in the night sky, even brighter than the full moon. Saturn reflects 47% of the light it receives, while the Moon only 12%. Saturn is so big that even at a distance of 55 million kilometers you can clearly see its characteristic shape. Mars at this distance is no more than a point. However, Saturn, with its stunning rings, is almost the same size as the Moon. Moreover, with the naked eye you can see not only Saturn itself, but also one of its satellites (bright dot at the top right). Months later, Saturn is already 1.5 million kilometers from Earth. At this distance, it even illuminates the dark side of the moon a little. One of the Moons of Saturn is Titan, one and a half times the size of our Moon, and it is already clearly visible in the sky. The orbit of Titan is at a distance of 1.2 million kilometers from Saturn, while our moon revolves around the earth at a distance of 300 thousand kilometers. Saturn is now about 1 million kilometers from Earth. A small moving dark spot on the surface of Saturn is a shadow from our Earth. Midtones are already clearly visible, because our Sun is not an ideal source of illumination. Light reflected from Saturn's rings hits the gas giant itself. The rings of Saturn are objects ranging in size from 10 cm to 10 meters, which are mostly made of ice. Therefore, as Saturn approaches the Earth, an incredible amount of flashes and traces of vapor particles from its rings are formed in the sky. The main ring of Saturn on the reverse side looks a little different. The thicker part of this ring does not allow light to pass through it, so it is darkened. In this case, the thinner part of the ring is lighter. Given the incredible size of this gas giant, as it moves away, it begins to block the Sun for a long time, the light of which barely breaks through the rings. In the end, the Sun will hide behind Saturn and a total solar eclipse will come, which will very clearly allow you to see all the beauty and grandeur of this incredibly huge planet.