Why is gravity so weak on the moon?
As a few people have already rightly pointed out – the simplest explanation for why gravity on the moon is weaker than gravity on Earth is because it is smaller than the earth and it really is as simple as that – the smaller the object, the less gravity it produces. Don’t get yourself too hung up on the thought that the gravity of Earth should make the gravity on the moon stronger. Gravity always pulls towards its source, so the gravity of the earth pulls towards the Earth (not just ‘down’ as we tend to think of it) where the gravity on the moon pulls towards the moon so more often than not the gravity of the Earth and the gravity of the moon will be pulling in different directions – so even if the Earth was close enough to the moon its gravity wouldn’t make the moon’s any stronger. I hope that’s easy to understand – I’ve tried to make it a simple as possible!
