Why are the eight planets Jupiter Saturn Uranus Neptune?

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, the first four belong to earth-like planets with small volume and high density, and the last four belong to wood-like planets with large volume and low density, which are gaseous. According to the farthest orbital radius of Neptune, the eight planets and the sun are all distributed in a nearly circular range with a radius of about 30 astronomical units.

brief introduction

According to the distance from the sun, we usually remember the eight planets in eight words: "water, earth, fire, wood, earth and sea." Of course, you can also remember these eight planets in series in other ways to form a poem: "Water overflows Jinshan, wood burns the earth, the sky and the sea are one, and the vast solar system.

These eight planetary classifications

1. Earthlike planets: Mercury, Venus, Earth and Mars. Earthlike planets have roughly the same structure, are similar to the earth, and all have rocky land, so they are called terrestrial planets.

Woodlike planets: Jupiter, Saturn, Uranus and Neptune. These planets are all gas planets similar to Jupiter, which are much larger than terrestrial planets. Because Jupiter and Saturn are different from Uranus and Neptune in many places, woody planets are divided into two categories: 1, giant planets, referring to Jupiter and Saturn; 2. Distant planets refer to Uranus and Neptune.