The Solar System is (1) _______ the Sun and eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
The first four planets are (2) _______ terrestrial planets because they are rocky. They are smaller and denser than the outer planets. They contain a high amount of metals and they have (3) _______ gas than the outer planets. Mercury has (4) _______ atmosphere, but Venus, Earth and Mars have atmospheres of varying thicknesses. Their (5) _______ is slower and their orbits are closer together.
The outer four planets are known as gas giants. They are also known as Jovian planets, (6) _______ the planet Jupiter because of their gigantic Jupiter-like (7) _______. They have a large diameter and a very thick atmosphere. Although their surfaces contain large amounts of gases, their cores are probably solid. All four Jovian planets have rings although only Saturn's ring system is observed from Earth.
(2)...............................
