Hua Feng discovered that the long-term study of the solar system has divided into the following disciplines:

Solar System Chemistry: An important sub-discipline of space chemistry that studies the chemical composition (including material origin, elemental and isotopic abundances) and physico-chemical properties of the solar system bodies, as well as chronological and chemical evolution issues. Solar system chemistry is closely related to the origin of the solar system.

Solar System Physics: The study of the physical properties, chemical composition, and cosmic environment of planets, moons, asteroids, comets, meteors, and interplanetary matter in the solar system.

The law of gravitational force in the solar system: The law of gravitational interaction between the celestial bodies in the solar system.

The problem of the stability of the solar system: one of the fundamental problems of astronomical evolution and celestial mechanics.

Although scholars agree that there are other celestial systems similar to the solar system, it was not until 1992 that other planetary systems were discovered. Hundreds of planetary systems have been discovered so far, but detailed information is scarce. The discovery of these planetary systems relies on the Doppler effect, which analyzes the changes in the speed of star motion by observing the periodic changes in the spectrum of stars, and deduces whether there are planets based on this, and can calculate the mass and orbit of the planets. Applying this technology, only Jupit-level planets can be found, and planets the size of the Earth cannot be found.

In addition, another purpose of the study of celestial systems similar to the solar system is to explore whether life exists on other planets.

Mercury is the planet closest to the sun, because Mercury is too close to the sun, the surface temperature is very high, the spacecraft is not easy to approach, and it is not easy to observe on the earth, because the observable time is concentrated in the first few minutes of the sun in the morning, and the few minutes after the sunset, the time is not easy to master, and in the case of high background brightness, it is not easy to find a Mercury that is not much bigger than the moon.

Mercury is the closest planet to the Sun, so it moves faster than any other planet, at nearly 48 kilometers per second, and orbits the Sun in less than 88 days. Mercury is very small, made of rock, and its surface is covered with craters and craters formed by meteor impacts, plus smooth, sparsely cratered plains. There are also ridges on Mercury's surface, which were formed by the gradual cooling and contraction of the planet's core 4 billion years ago, so the surface is undulating. Mercury rotates very slowly, nearly 59 Earth days in one rotation, so one solar day on Mercury (from sunrise to sunrise) is almost 176 Earth days — twice as long as Mercury's 88 days in a year. The surface temperature of Mercury varies widely, reaching as high as 430 degrees Celsius on the sunny side and -170 degrees Celsius on the dark side. When night falls, the temperature drops quickly because Mercury has almost no atmosphere. The composition of the atmosphere consists of trace amounts of helium and hydrogen, captured by the solar wind, and perhaps a little of other gases.

Venus is the second planet in the solar system, the brightest planet in the whole day is Venus, usually in the early morning or evening can be seen, the brightest brightness can exceed -4, like a street lamp hanging on the side of the mountain, the general telescope can be observed, often can see the waxing and waning phenomenon such as the moon. In the ancient Western world, Venus represented the beautiful goddess Venus is a rocky planet and the second closest planet to the Sun. Venus rotates slowly in the opposite direction as it revolves around the Sun, making it the planet with the longest rotation period in the solar system, taking about 243 Earth days.

Venus is slightly smaller than Earth, and its internal structure may be similar. Venus is the brightest object in the sky after the Sun and the Moon, because its atmosphere reflects sunlight strongly. The main component of the atmosphere is carbon dioxide, which absorbs more heat under the greenhouse effect, making Venus the hottest planet, with a high surface temperature of 480 degrees Celsius. The thick clouds contain small droplets of sulfuric acid and are blown by the wind at a speed of nearly 360 kilometers per hour. While Venus takes 243 Earth days to make one rotation, high-speed winds can blow clouds around the planet in just 4 Earth days. High temperatures, acid clouds, and extremely high atmospheric pressure, (about 90 times the Earth's surface), indicate the harsh environment of Venus.

The earth is the third planet in the solar system, there is a moon called the moon, and the protection of the earth's atmosphere and the proper position from the sun are important conditions for the origin of life.

Earth is the third farthest planet from the Sun, the largest rocky planet with the largest diameter and proportion, and the only planet known to have life. The rocks and metals in the Earth's interior show that it is a typical plate composition, and due to the pushing of the plates, there is seismic and volcanic activity at the junction.

The Earth's atmosphere is the same protective layer, which blocks the sun's harmful radiation and prevents meteors from hitting the planet's surface, and in addition to storing enough heat to prevent the temperature from dropping sharply. Seventy percent of the Earth's surface is surrounded by water, and no other planet has found this liquid form of water on its surface. The Earth has a natural satellite, the Moon, whose surface is covered with large and small craters, and the Moon is large enough to treat the two celestial bodies as a double planetary system.

The earth also has a geomagnetic field, and the north and south poles of the current geomagnetic field are just the opposite of the geographical north and south poles, and the geomagnetic field is also protecting life on the earth.

Mars is the fourth planet in the solar system, and in the clear night sky, Mars, which represents the god of war, shines with fire-colored light, attracting the attention of millions of people in ancient and modern times. 100,000 years ago, a rock from Mars fell in the Antarctic region of the Earth and froze. People have found in this meteorite, it may be a trace of life fossils, this fossil was formed on Mars three billion years ago, scientists are actively researching, and probing this planet full of mysterious rivers and volcanoes on the surface, was there ever life on Mars?

Mars is the second smallest planet in the solar system, about one-half the diameter of the Earth, about one-tenth of the volume of the Earth, and the gravity on the surface is about one-third of that of the Earth. The atmosphere of Mars is thinner than that of Earth, only one hundredth of the Earth's atmosphere, and its main component is carbon dioxide. There are also a small amount of clouds and morning fog. Because the atmosphere is very thin, the greenhouse effect is not obvious. The surface temperature of Mars at the equatorial surface can reach a maximum of 27°C during the day and a minimum temperature of -133°C at night.

The northern hemisphere of Mars has many large plains formed by solidified volcanic lava, the southern hemisphere has many craters and large impact basins, and several large, extinct volcanoes, such as Mount Olympus, which is 600 kilometers wide, and many canyons and bifurcating river beds.

Canyons are caused by the movement of the earth's crust, and riverbeds are generally thought to have been formed by rivers that have dried up. At high latitudes on Mars, carbon dioxide in the atmosphere freezes in the winter when temperatures are too low, forming clouds at an altitude of 50 kilometers and disappearing in spring. In summer, due to the strong sunshine, the ground temperature is very high, and the atmosphere near the ground is heated and generates strong updrafts. This air flow will roll up the dust on the ground, absorbing the heat of the sun in the air and further increasing the temperature of the atmosphere, so that the rate of rise is faster, so large-scale storm sand can often be seen on Mars.

The largest volcano on Mars------- Mount Olympus, rises 24 kilometers above the ground, almost three times the highest mountain on Earth (about 8,844 meters), and is also the highest mountain in the solar system.

Jupiter is the fifth planet in the solar system and the largest planet in the entire solar system, located between Mars and Saturn, with a general astronomical telescope (60mm 72 times) you can see the stripes on its surface and four bright moons, it is the second brightest planet in the whole day after Venus, Jupiter's brightness can exceed -2 at most. Jupiter is the fifth planet farthest from the Sun and the first of the four gas planets.

It is the largest and heaviest planet, 11 times the diameter of Earth and 2.5 times the mass of the other eight planets combined. Jupiter may have a small stony core surrounded by an inner mantle made of metallic hydrogen (liquid hydrogen, similar in nature to metal). Outside the inner mantle is an outer mantle made of liquid hydrogen and helium, which fuse into a gaseous atmosphere.

Jupiter's rapid rotation causes clouds in the atmosphere to form bands and zones of turbulence to form special clouds such as white and red spots, both of which are huge storms. The most famous cloud is a storm called the Great Red Spot, which consists of a swirling cylindrical cloud three times wider than the Earth and rising about seven kilometers above the high clouds.

Jupiter has a thin, dark main ring with a thin ring of particles that extend toward the planet. As of 2013, there are 66 known satellites. The four largest moons (known as Galileo Woodymede) are Gannebad, Calis, Io, and Europa.

Gannybade and Callistos have many craters on their surfaces, and perhaps ice. The surface of Europa is slippery, covered with ice and perhaps water. There are many glowing red, orange, and yellow spots on Io's surface. These colors come from the sulphurous material of active volcanoes, caused by the ejection of fluffy lava hundreds of kilometers above the surface.

Saturn is the sixth planet in the solar system and the second largest planet, with beautiful rings that can be seen from a normal telescope on Earth, Saturn, Jupiter, Uranus and Neptune are all gases on the surface, so they all rotate quite quickly. Saturn's rings are mainly made up of ice and dust particles, and scientists speculate that one of the moons may have been unable to withstand Saturn's strong gravitational pull and disintegrated into fragments.

Saturn's ring plane is not on the same plane as Saturn's orbital plane, so when Saturn's orbit is in a certain position, Saturn's ring plane is just parallel to our line of sight, and we can't see this Saturn ring on Earth, because Saturn's ring is so thin that we can't see it from the side, and when Saturn's ring is parallel to the sun, we can't see it because the ring plane doesn't receive light.

Saturn, the sixth planet counted from the Sun and an almost as big a gas giant as Jupiter, is about 120,500 kilometers in diameter at the equator. Saturn may have a small core of rock and ice, surrounded by a metallic hydrogen (liquid hydrogen, similar in nature) to the interior. Outside of the Inland Chamber, there is an Alien Chamber, which is composed of liquid hydrogen, which is fused into a gaseous atmosphere.

Saturn's clouds form bands and zones, similar to those of Jupiter, but are blurred by the thinness of the outer clouds. Storms and whirlpools occur in clouds and appear red or white ovals.

Saturn has an extremely thin but wide ring system, which is less than a kilometer thick but extends about 420,000 kilometers outward from the planet's surface. The main ring consists of thousands of narrow rings made up of small particles and blocks of ice as large as several meters wide. Saturn has 62 moons, some of which orbit within the ring, which exerts gravity that affects the shape of the ring. Interestingly, 7 of the satellites are in the same orbit and share the same orbit with other satellites. Astronomers believe that these satellites in shared orbit are satellites from the same but later fragmented.

Uranus is the seventh planet in the solar system, and before the arrival of the spaceship, humans did not know that it also has rings as beautiful as Saturn, and Uranus is the farthest planet that humans can see with the naked eye, but it is difficult to find it if you are not professionally trained.

Uranus (U

a

us) is characterized by a large inclination of the rotation. Generally, the rotation axis of the planet is very close to its rotation plane, but the rotation axis of Uranus is inclined at 98 degrees, almost lying horizontally. As a result, the sun sometimes shines on the North Pole all day, while the Southern Hemisphere is dark all day.

Uranus's surface glows with a bluish-green tinge tinge, so it is speculated that its atmosphere may contain a lot of methane. Uranus, on the other hand, is about four times the diameter and 14 times the mass of the Earth, but less than a quarter of the density of the Earth, because Uranus, like other Jupiter-type planets, is formed from gases such as hydrogen and helium.

There are also nine rings above the equator of Uranus, which together are about 100,000 kilometers wide and about one-third the width of Saturn's rings. The structure and composition of Uranus's rings are very different from those of Saturn and Jupiter, which are formed by thousands of rings sandwiched between very narrow gaps, while Uranus's nine rings are far from each other. Eight of the nine rings are about a dozen kilometers wide, and the outermost one is more than 100 kilometers wide.