Большая звезда по имени Солнце притягивает к себе все естественно созданные космические объекты, включая планеты, которые кружатся вокруг нее. Планета — это небесное тело округлой формы, которое по орбите вращается вокруг звезды. Сама ее форма сформирована этим вращением.
We know from our high school astronomy course that there are eight planets in the solar system. Some of them have satellites. Not everyone remembers which of them are the largest planets in the solar system. Let's refresh our memories and tell us some interesting facts.
A comparative table of the characteristics of the planets
There are two groups of planets in our system:
- terrestrial (4 closest to the star);
- gas (4 remote).
There are also dwarf planets, they are too small and weak, so other objects fall into the area of their orbits. Scientists clearly identify 5 dwarfs, but it is known for sure that there are more in our system.
Planets of the solar system relative to the Sun and dwarf planets
The largest are the planets of the gas sector, the planets of the terrestrial group seem dwarfed in comparison.
It is noteworthy that scientists have now excluded Pluto from the category of planets. Today it is one of the dwarfs. Below we will tell you about it and its size.
| Planet | Radius, km | To the sun, million km | Consists of | Compared to the Earth |
|---|---|---|---|---|
| Mercury | 2440 | 57,91 | From the iron core, which has a magnetic field, the surface is covered with craters | 0.055 mass |
| Venus | 6052 | 108 | The surface is similar to Earth's, but the conditions are different: everything here is covered with lava | 81.5% of Earth mass |
| Mars | 3390 | 228 | There are rocks and ice on the surface, there are large seas, the composition is not studied | Half as much. |
| Earth | 6371 | 149,6 | Плотная структура с магнитным полем. Внешняя структура — преимущественно силикат | — |
| Saturn | 58232 | 1,434*Е3 | Hydrogen with an admixture of helium, methane, water forms the basis | 9.4 times the size of the Earth |
| Uranus | 25362 | 2,879*Е3 | Iron core covered with ice gas of different types | Four times the size |
| Jupiter | 69911 | 778,5 | Hydrogen, methane, water, and ammonia | 11 times larger in size |
| Neptune | 24622 | 4,503*Е3 | Consists of gases | Almost four times as much |
A few words about Pluto: many remember it as the smallest planet, in 2006 it lost this status, because it did not meet the characteristic of size compared to other objects in the field of its orbit. Pluto was almost the smallest object in the Kuiper Belt. This decision, although scientifically confirmed, has caused a lot of ridicule towards the International Astronomical Union.
NASA probe photo of Pluto excluded from the list of planets
Pluto is 2,377 kilometers in diameter, about six times smaller than our planet's satellite and composed of rock and ice.
8 место — Меркурий (d=4879 км)
The smallest planet in the solar system, this status only passed to Mercury in 2006 when Pluto was reclassified as another object. This planet looks very similar to the Moon: the surface is rocky and covered with craters.
Despite its small size, Mercury has a relatively large mass (3.3*1023 It is as close as possible to the brightest star in the system, the Sun, and has no satellites of its own.
Mercury's surface is riddled with craters and resembles the moon's
Man could not survive on it, because when it rotates, it is almost perpendicular to the Sun, there is no change of seasons. On one side, facing the light is hot to +430 ° C, on the other, the dark side, the cold reaches -190 ° C.
7 место — Марс (d=6779 км)
You can easily see the red planet from our planet without a telescope. It has two satellites at once:
- Deimos;
- Phobos.
Scientists in the XX century studied the body well, made a detailed map, with the right telescope and a competent formula for observing Mars can see even an amateur.
Mount Olympus on Mars was formed about 3 billion years ago
It takes a little longer (2.7%) for a planet to wrap around the Sun than it does for ours. In this, they are similar. Since it additionally rotates around its axis at an inclination, the seasons change on its surface.
Для человека температурный режим Марса приемлем: на экваторе это +25-35°C, к полюсам температура снижается вплоть до -150°C. Ученые предполагают, что в будущем человечество сможет жить на другой планете, и ею будет Марс. Один нерешенный вопрос — радиация на его поверхности слишком высока.
6 место — Венера (d=12104 км)
Venus, like Mercury, Earth, Mars belong to the group of terrestrial planets. It is the second from our star. It differs from the other seven bodies in that it orbits itself in the opposite direction. In natural light, it is white and blue, so it is clearly visible from Earth. It was known to mankind since time immemorial.
Сравнительные размеры земных планет (Венера — вторая слева)
Also, Venus is characterized by high pressure. On the surface, it would be as hard for a person as if he were at the depth of the ocean in a depression of about 1 km. It is the earliest object of interplanetary exploration.
The climate is characterized by high surface temperatures (over 400 degrees Celsius). There is a hypothesis that Mercury was once a satellite of Venus.
5 место — Земля (d=12742 км)
Our planet can be called the most beautiful planet in the solar system. It is covered with vegetation, it is inhabited by living organisms. Scientists do not know another such body even on the scale of the universe. The density of the planet is 5.51 g/cm3which is the maximum for the entire system.
Night Earth, view from the ISS
У Земли всего один спутник — Луна, она размером с четверть Земли. на планете есть сменяемость времен года, дня и ночи. Впервые собственную планету из космоса увидел Юрий Гагарин в 1961 году. Для наблюдения и изучения Земли из космоса служат спутники и космические станции.
4 место — Нептун (d=49244 км)
The heaviest and farthest from a star planet in our system, Neptune is large, blue, and cold. It is composed of gases of varying densities. Its inner core is hotter, which explains its average temperature of -221°C.
Wind gusts on the planet can reach 2,100 km/h
Замечено, что на планете действуют изменения погоды, свирепствуют штормы, ветры. Порывы ветра самые сильные в Солнечной системе. Такая активность стала возможной благодаря внутреннему нагреву. У Нептуна 14 спутников, вращающихся вокруг него. Самый крупный — Тритон. Кстати, открыли Нептун без телескопа, а при помощи математических вычислений.
3 место — Уран (d=50724 км)
It has a similar gas composition to Neptune, with large amounts of ice of the following types present inside:
- methane;
- ammonia;
- water.
Comparison of the size of the Earth and Uranus
Центр планеты — каменное ядро. Лед не плотный, внутреннее тепло ядра не выражено ярко, что позволяет назвать Уран самой холодной планетой Солнечной системы. Известно о 27 спутниках ледяного гиганта, которые не являются чрезвычайно крупными, как, например, тот же Тритон. У Урана есть кольца, как и у всех газовых планет.
2 место — Сатурн (d=116464 км)
Сатурн, Уран и Нептун — самые дальние планеты от Солнца. Сатурн известен большими кольцами, наклоненными под углом 28° и состоящими из мелких частиц, вращающихся по орбите.
Стрелочкой показана Земля. Вид на нашу планету со станции «Кассини» недалеко от Сатурна
Сатурн — газовый гигант, который вращается вокруг Солнца (полный оборот делает за 29,5 лет). У него низкая плотность, меньше, чем у воды. Основной газ — водород. Плотного тела у планеты нет. Атмосфера газового гиганта состоит из этих же газов. Открыты 62 спутника, самые большие — Титан, Гиперион.
1 место — Юпитер (d=139822 км)
Юпитер — самая большая планета нашей системы, назван в честь древнеримского бога, схожего с древнегреческим Зевсом.
Comparison of the size of the Earth and Jupiter
What is known about Jupiter
Jupiter's radius is equal to 11 Earth radii, all processes on it are several times greater than on Earth. For example, a giant storm is visible in the atmosphere as a red spot. It has existed for a long time and is twice as large as the Earth. Wind speed reaches 600 km/h. Jupiter is so large that a person can see the celestial body without a telescope from Earth.
A feature of the big planet is its stripes.
Фото Юпитера 1979 года, сделанное со станции «Вояджер-1»
Jupiter Rings
All large gas planets have rings, which are composed of moving small particles. Jupiter's rings are poorly pronounced; only the Voyager spacecraft was able to distinguish them when it entered the atmosphere.
Jupiter's satellites
There are 79 known satellites:
- Europe;
- Eo;
- Callisto;
- Ganymede.
Scientists are interested in exploring Europe, where the ocean is found. Theories are being advanced about the existence of life on Europe.
Космос — мир, в котором наша планета — лишь частичка. Изучать его можно при помощи аппаратов, а можно просто разглядывать интересные объекты на небе.