1. Pluto is very small: Many people think that Pluto is very small, like an ordinary asteroid. In fact, the diameter of this dwarf planet is 2360 kilometers, which is two-thirds of the diameter of the moon and Europa. three-quarters of the diameter. Charon, Pluto's largest moon, has a diameter of approximately 1,207 kilometers.

2. Pluto was once a "satellite" of Neptune: In 1965, researchers discovered an orbital oscillation - there is an optimal gravitational point in the orbit between Pluto and Neptune. This orbit*** Vibration can prevent two planets from getting too close to each other.

3. Pluto is an icy planet: Pluto’s surface is covered with a large amount of ice, including frozen nitrogen and methane, but the overall density of Pluto is twice that of ice water. The mass of this dwarf planet is composed of Made of two-thirds rock and one-third ice water, Pluto is precisely a rocky planet with an icy shell.

4. Pluto is always “dark”: Pluto’s orbit is about 4.8 billion kilometers away from the sun, so many people speculate that the surface of the planet has always been dark.

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

Extended information:

Pluto (asteroid serial number: 134340 Pluto; astronomical code: ?, Unicode code: U+2647) is a dwarf planet in the Kuiper Belt. Pluto was the first Kuiper Belt object discovered.

Pluto is the largest and second most massive dwarf planet known in the solar system. Among objects orbiting directly around the Sun, Pluto ranks ninth in size and tenth in mass. Pluto is the largest overseas celestial body, second only in mass to Eris, which is located in a discrete disk. Like other Kuiper Belt objects, Pluto is composed primarily of rock and ice.

On July 14, 2015, the New Horizons probe launched by NASA flew by Pluto, becoming the first human probe to visit Pluto.

On March 4, 2016, the NASA "New Horizons" probe project team recently discovered that the top of Pluto is also covered with "white snow."

Baidu Encyclopedia—Pluto