Question

What are planets? State any four characteristics of a planet.

Answer 1

1. Planets- The word planet comes from the Greek word which means wanderer.
2. According to the International Astronomical Union (IAU), a celestial object is called a planet if,
   2.1. It has a fixed clear orbit around the sun.
   2.2. It is massive enough for the gravity to make it round.
   2.3. It should not take more than two centuries to revolve around the sun.
3. Therefore there are eight planets in the solar system- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Four characteristics of a planet.

1. Planets are round and opaque celestial bodies that revolve around the sun in a fixed orbit.
2. Planets rotate around their own axis.
3. Planets also revolve around the sun.
4. Planets are not self-luminous like stars.