SOLAR SYSTEM

Detailed explanation-1: -From top: Mercury, Venus, Earth and Mars. The planets Mercury, Venus, Earth, and Mars, are called terrestrial because they have a compact, rocky surface like Earth’s terra firma. The terrestrial planets are the four innermost planets in the solar system.

Detailed explanation-2: -Mercury, Venus, Earth, and Mars are the planets closest to the Sun. They are called the inner planets.

Detailed explanation-3: -The temperature of the early solar system explains why the inner planets are rocky and the outer ones are gaseous. As the gases coalesced to form a protosun, the temperature in the solar system rose. In the inner solar system temperatures were as high as 2000 K, while in the outer solar system it was as cool as 50 K.

Detailed explanation-4: -Venus is the second planet from the Sun and is Earth’s closest planetary neighbor. It’s one of the four inner, terrestrial (or rocky) planets, and it’s often called Earth’s twin because it’s similar in size and density.

Detailed explanation-5: -The four inner planets, those closest to the Sun, are Mercury, Venus, Earth, and Mars. They are smaller and composed mainly of metals and rocks.