Questions tagged [movement]

Today I saw something that passed like a jet. But am sure it's not so because jet will leave a long track of its passage. It moved in a straight line with sparkling track and what I saw was observed even from 200kms away from my destination. What…

Why are planets moving in the first place? Gravity causes them to orbit, but why move at all? note: this is not a question on why planets orbit each other, I know the reason for that is gravity. What I'm asking is why do planets move at all? For…