Question

Why is thermal escape of atmospheric gas much easier from the Moon than from Earth?

A) The Moon's gravity is so much weaker than Earth's.
B) The Moon's average surface temperature is lower than Earth's.
C) The Moon lacks a global magnetic field, while Earth has one.
D) Outgassing on the Moon releases gases with lower masses than does outgassing on Earth.

Answer 1

The thermal escape of atmospheric gas is easier from the Moon due to its weaker gravity and lack of a global magnetic field.

Step-by-step explanation:

The reason why thermal escape of atmospheric gas is much easier from the Moon than from Earth is because of the Moon's weaker gravity (option A) and smaller mass. The Moon's gravity is only one-sixth of Earth's, making it easier for the moving molecules of gas to escape into space. In addition, the Moon lacks a global magnetic field (option C), which can help trap and retain atmospheric gases like Earth does. Therefore, option A (The Moon's gravity is so much weaker than Earth's) and option C (The Moon lacks a global magnetic field, while Earth has one) are both correct.