it is said that there is no gravity in outer space. then why dont planents coollide with each other?
Kindly refer to the question no. 6 in the link given below for an answer to a similar query :
https://www.meritnation.com/ask-answer/question/1-a-star-is-light-years-away-from-the-earth-what-does-it-m/stars-and-the-solar-system/3588802
https://www.meritnation.com/ask-answer/question/1-a-star-is-light-years-away-from-the-earth-what-does-it-m/stars-and-the-solar-system/3588802