The inner planets are relatively small planets composed mostly of rock. They are: Mercury, Venus, Earth, and Mars. These planets have few or no moons.
1. Mercury is small, hot, has almost no atmosphere, and no moon.
2. Venus, the hottest planet, is almost as big as the Earth, but has an extremely thick, unbreathable atmosphere and sulphuric acid rain (and no moon). 3. The Earth is the third planet from the Sun. It has one large moon. 4. Mars is a small, red planet with a thin atmosphere and two tiny moons.
What is the hottest planet in our Solar System?
Try Again! On average, Mars is a little colder than the Earth.