Explanation:

In our Solar System, astronomers often split the planets into 2 groups — the inner planets and the outer planets. The inner planets are nearer to the Sun and are smaller and rockier. The outer planets are farther away, larger and made up mainly of gas. The inner planets (in order of their distance from the sun, from closest to furthest) are Mercury, Venus, Earth and Mars. Than an asteroid belt comes after that the outer planets, Jupiter, Saturn, Uranus and Neptune.

* The four inner planets are known as terrestrial planets because their surfaces are solid (and, as the name signifies, somewhat similar to that of the Earth — although the term can be misleading because each of the four has mostly different environments). They were made up mostly of heavy metals such as iron and nickel, and consists of either no moons or few moons.

* The outer planets (sometimes known as Jovian planets or gas giants) are big planets swaddled in gas. They all possess rings and all of majority of moons each. Despite of their size, only 2 of them are visible without the telescopes: Jupiter and Saturn. Uranus and Neptune were the first among the planets which got discovered since antiquity, and displayed astronomers the solar system was bigger than they previously thought.