Why does Pluto differ from the outer planets?

Answer 1

Pluto has a solid surface of rock and ice. It does not have a vast gaseous atmosphere.

The four smaller planets closer to the Sun are basically solid or rocky objects, while the four largest planets are all gas giants with deep, dense, swirling atmospheres. Pluto's solid surface, onthe other hand, more closely resembles that of the small, dense planets.

The four outer planets; Jupiter, Saturn, Uranus and Neptune; are all enormous planets largely made of gas and liquid. They travel round the Sun in nearly-circular orbits, widely spaced out. They all have rings and a system of many moons, and while asteroids and comets cross their orbits they are by far the biggest thing in their orbital zone.

Pluto, on the other hand, is tiny: smaller than our Moon. It is made up of a mixture of rock and ice, and has a solid surface you can stand upon. Its orbit is highly elliptical, tilted from that of the other outer planets, and it crosses the orbit of Neptune. It has a thin atmosphere, four moons, and no rings. Moreover, Pluto shares its orbit with thousands of other bodies ranging in size from "dirty snowballs" a few kilometres in diameter up to Eris, an object the size of Pluto itself. This region where Pluto orbits is now called the Kuiper Belt. Because Pluto is so different from the other outer planets and is instead more like the objects in the Kuiper Belt, Pluto was reclassified from a planet to a Kuiper Belt object in 2006. Some astronomers, however, continue to hold that Pluto should be called a planet.

Answer 2

It does not have a vast gaseous atmosphere. The four smaller planets closer to the Sun are basically solid or rocky objects, while the four largest planets are all gas giants with deep, dense, swirling atmospheres. Pluto's solid surface, on the other hand, more closely resembles that of the small, dense planets.

Answer 3

Pluto is one of a large collection of small bodies past Neptune, some of which are called "plutoids" because they are similar to it. They are relatively small agglomerations of rock and frozen gases, and might not exist at all if they were closer to the Sun. These dwarf planets and planetoids resemble the inner planets in having a solid surface rather than the dense atmosphere found on the four large outer planets.

Answer 4

Pluto is not a planet, and it is different from the outer planets in the following ways:

1. Pluto has asteroids in its orbit
   
2. Pluto is not made of gas
   

Answer 5

1: It is smaller than the rest of the outer planets.

2: It is a rocky planet unlike all the other outer planets.

3: It has no rings.

4: It is a dwarf planet.