Well because 1. Pluto is too small and 2. its made of/covered with ice.
These planets are outer planets.
The outer planets.
it s an outer planet
The terms "outer planet" and "inner planet" are only used for planets. Pluto is not a planet, and it orbits beyond the outer planets.
Dwarf planets
The outer planets include: Jupiter, Saturn, Uranus, Neptune, and Pluto (a dwarf planet). They are mostly huge (besides Pluto) and mostly gaseous.
Inner planets are closer to the sun than the outer planets. Inner planets are Mercury, Venus, Earth and Mars. The outer planets are Neptune, Uranus, Saturn, and Jupiter (and maybe Pluto. The inner and outer planets are separated by a large distance and an asteroid belt. The inner planets are "rocky" the outer planets are gaseous (with the exception of Pluto.
The planet Pluto is the most outer planet in the solar system , so it is very ,very far indeed.
Pluto differs from the outer planets in that it is considered a dwarf planet, not a full-sized planet like the outer planets (Jupiter, Saturn, Uranus, Neptune). It also has a highly inclined and elliptical orbit compared to the more circular orbits of the outer planets. Additionally, it is much smaller in size compared to the outer planets.
There are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto ( maybe not, scientist are still trying to figure that out).Jupiter, Saturn, Uranus, and Neptune are the outer planets. The outer planets are separated from the inner planets due to the asteroid belt that lays between them.
The average sizes of the outer planets are smallest than the average size of the Pluto so that they can called them the dwarf planets.
The Outer/Jovian planets are as follows: * Jupiter * Saturn * Uranus * Neptune Pluto is not included anymore.