Why did Pluto disappear in the solar system?

1, Pluto is very small: many people think that Pluto is very small, like an ordinary asteroid. In fact, this dwarf planet is 2360 kilometers in diameter, which is two-thirds of the diameter of the moon and three-quarters of the diameter of Europa. Pluto's largest satellite Phobos is about 1207 km in diameter.

2. Pluto was once the "satellite" of Neptune: 1965. Researchers found an orbital vibration-there is an optimal gravitational point between Pluto and Neptune. This orbital vibration can prevent the two planets from getting too close to each other.

3. Pluto is an icy planet: Pluto is covered with a lot of ice, including frozen nitrogen and methane, but the density of Pluto is twice that of ice water as a whole. The mass of this dwarf planet consists of two-thirds of rocks and one-third of ice water. Therefore, Pluto is just a rocky planet with an ice shell.

4. Pluto has always been in the dark: Pluto's orbit is about 4.8 billion kilometers away from the sun, so many people speculate that the surface of this planet has always been in the dark. Alan Stern, director of the New Horizon Detector Program at the Southwest Research Institute in Colorado, said, "That's not the case. Even at noon, the sunlight on Pluto is lower than people expected. It may be like very dark weather or dusk on earth. "

5. Pluto lacks air: In the 1980s, researchers discovered that Pluto has an atmosphere, which mainly contains nitrogen, just like the earth's atmosphere. But Pluto's air also contains carbon monoxide and methane, which is thinner than the earth's atmosphere and extends more to the space environment.

6. Pluto's orbit is peaceful: Pluto's orbit is elliptical, with the nearest distance from the sun of 4.43 billion kilometers and the farthest distance of 7.3 1 100 million kilometers. The inclination of the dwarf planet's orbit relative to the ecliptic (the earth's orbital plane around the sun) is 17 degrees. In addition, Pluto's orbital parameters are completely different from those of the other eight planets in the solar system.

Extended data:

The discovery of Pluto:

1In the 1940s, Auburn Levi analyzed the perturbation of Uranus orbit through classical mechanics and predicted the position of Neptune. /kloc-at the end of 0/9, astronomers speculated that other planets disturbed Uranus' orbit based on their observation of Neptune.

1906 Percival Lowell, the founder of Lowell Observatory, began to look for the ninth planet, Planet X. 1909 Lowell and william henry pickering proposed some celestial coordinates where the celestial body might be located. This search continued until Lowell died in 19 16, but there was no result.

During the March 19 19, 2005, two photos of blurred Pluto images were taken, but these images have not been correctly recognized. There are 15 known photos of this forward reconstruction, which can be traced back to1photos taken by Yekeshi Observatory on August 20th, 909.

Lowell's widow, constance Lowell, tried to get all her husband's shares in the observatory. The search for planet X didn't resume until 1929, because of the legal dispute caused by it. Visto Shriver, then director of the Observatory, handed over the task of searching for Planet X to Tombo after seeing the astronomical drawing samples of clyde tombaugh.

Tombo's task is to systematically take photos of the night sky in pairs and analyze the celestial bodies whose positions change in each comparison. With the help of scintillation comparator, Tombo quickly changed the photosensitive plate and searched for the position change or appearance change of celestial bodies. 1930 February 18, after nearly a year's search, Tang Bo found a possible moving celestial body in the photos taken on June 23rd and1October 29th of that year.

65438+1October 2 1 day A poor quality photo confirmed the motion of celestial bodies. After further verification photos were taken by the Observatory, the news of the discovery of the ninth planet was sent to the Observatory of Harvard University by telegraph on March 1930.

Baidu Encyclopedia-Pluto