1) The Four Inner Planets of the Solar System Are Solids and Smaller in Size. Why?
- The inner planets are closer to the Sun.
- The materials which can survive in the extreme heat produced by Sun combine to form the inner planets, and most of them are metals and rocks.
- This aggregation of metals and rocks makes the inner planet smaller and rocky.
2) Why Are There Fewer or No Moons for the Inner Planets?
- The inner planets are smaller and denser than all the planets in the solar system.
- Thus they do not have enough gravitational force to attract any celestial body or a Moon. Hence they have significantly less or no moon.
3) Why Is Mars Called the ‘Red Planet’?
- The soil on mars is very rich in rust due to the presence of iron in the soil.
- This large amount of rust in the soil gives it its characteristic red colour.