Please refer to the quoted article: The Mystery of Uranus, Neptune and Pluto.
More than a hundred years ago, Saturn was considered as the boundary of the solar system. It was not until 178 1 that Uranus was found in the ruins that the territory of the solar system extended to the depths of the universe. Uranus, Neptune and Pluto are the three farthest planets known in the solar system so far. Because they are more than 3 billion kilometers away from the sun, it is difficult for ordinary people to see with the naked eye, so they are also the last three planets to be discovered. However, if your eyesight is particularly good, you should choose a clear moonless night where you can vaguely see Uranus.
Uranus is 2.88 billion kilometers away from the sun and 2.73 billion kilometers away from the earth. It takes 2 hours and 38 minutes for the sun's rays to reach Uranus. Tiangong has a maximum radius of 25,000 kilometers, its volume is 65 times that of the Earth, and its mass is 15 times that of the Earth.
Uranus is a blue-green planet. This is because the alkane cloud composed of hydrogen and helium in the atmosphere absorbs red light.
The moons of Uranus are unusual in the solar system. There are many craters on the big satellite, and there are a lot of severe and complicated crustal structural faults. Uranus' running posture is also unique. Generally, planets revolve around the sun sideways, while Uranus rotates in its orbit, just like a bowling alley.
American Voyager 2 flew to Uranus for the first time in 1986, and it also gained a lot.
(1) Uranus also has a strong magnetic field. Like Saturn, Jupiter and the Earth, the magnetic field is distorted and skewed, and the magnetic field intensity is only 1% of the Earth's.
(2) Uranus has many huge craters-there are many huge craters on the surface of the lying king star, and there are obvious fault areas and valleys on its large satellites, which shows that Uranus has been strongly attacked by meteors.
Uranus has the phenomenon of "electric glow"-Saturn has also had it, and Uranus has also discovered the phenomenon of glow, but the characteristics of "electric glow" are very different from the aurora of the earth. Neptune and Pluto were not first seen by astronomers, but first calculated by scientists, and then searched for a needle in a vast sea of stars. Neptune was captured in 1846, and Pluto appeared in 1930, more than half a century later. So these two planets are also called "planets discovered by the tip of a pen", which makes them look different.
Neptune has a radius of about 24,600 kilometers, which is 57 times that of the Earth and 77 times that of its mass.
1In August, 989, Voyager 2 came to Neptune, which brought us unprecedented information. Neptune is also very beautiful. It has four rings and L dust shells, surrounded by eight satellites, and there are clouds and storms in the atmosphere. In Neptune's atmosphere, there are three obvious bright spots, two dark spots and a big black spot. The oval dark spot is about t.28 kilometers in diameter, similar to Jupiter's erythema and looks like black eyes. Therefore, it is relatively called "Neptune with big black spots". The most intriguing is its two satellites "Triton" and "Triton". With a diameter of 2,720 kilometers and a surface temperature below minus 24 degrees, Triton is by far the coldest celestial body known in the solar system.
The most interesting thing about Triton is its dark stripes like feathers, all pointing northeast. Scientists believe that it is the result of wind erosion on the lee side, or because of the arrival of spring, the polar ice in the south of Triton melts and the nitrogen deposits under the surface expand rapidly.
Triton has been one of the celestial bodies concerned by scientists.
Triton is much smaller, with a diameter of 400 kilometers. Triton is unique in its orbit and brightness. Its orbit is a flat ellipse with an eccentricity of 0.75, which is flatter than that of all other satellites. The closest distance to Neptune is only 1.4 million kilometers, and the distance is 9.7 million kilometers.
The brightness of Enceladus changed 34 times in 8 days and nights in a measurement in July 1987, which is really puzzling.
Pluto is the farthest planet from the sun among the nine planets. It takes five and a half hours for the sun to reach here, so it is very cold here, and the temperature is as low as MINUS 240'. Pluto is about 2220 kilometers in diameter and two thousandths of the mass of the earth, so it is extremely small in the solar system. Because it's far and small, it's hard to find.
The brightness change of ghost stars is very strange. Since Pluto was discovered, it has been moving towards Yingkou point. It is reasonable to say that the brightness should be brighter and brighter, but it has become more and more fascinating. Yuxing's satellite is unique. Its satellite is ice in proportion to its diameter, which is unique in the solar system.
The most puzzling thing is that period of revolution and Pluto have exactly the same rotation period, which is 6.39(6 days and 9 hours 17 minutes). Coincidentally, Pluto's orbital plane coincides with Pluto's equatorial plane, and Pluto's rotation period is as long as its period of revolution. Therefore, rather than saying that Ghost 7 revolves around Pluto in its own orbit, it is better to say that the two are "circling each other", just like two people holding hands and dancing face to face in circles. Pluto's Rotation Period _ Pluto's rotation period is exactly the same as Pluto's period of revolution, and this "triple" synchronization is similar, and it is unique in the solar system.
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