MCQ Detailed View

A planet can retain its atmosphere depending mainly on two important factors: the strength of its gravity and the temperature of its atmosphere. Gravity is the force that pulls gases towards the planet’s surface. If a planet has strong gravity, it can hold onto its gases more effectively, preventing them from escaping into space.

Temperature also plays a key role. When the atmosphere’s temperature is low, gas molecules move slower and have less energy to escape the planet’s pull. But if the temperature is high, the gas molecules move faster and can escape more easily, even if the planet’s gravity is strong.

Therefore, a planet retains its atmosphere best when its gravity is strong and its atmospheric temperature is low. This balance allows gases to stay near the surface instead of drifting away.

If gravity is weak, gases will escape quickly regardless of temperature. Similarly, if temperature is very high, gases may escape even if gravity is moderate. This is why small planets like Mercury have almost no atmosphere, while larger planets like Earth and Jupiter have thick atmospheres.

Understanding these principles helps explain the differences between planetary atmospheres in our solar system and beyond. It is a fundamental concept in physics, especially in the study of planetary science and space environments.