Big, small. Hot, cold. The 8 planets in our solar system differ in lots of ways, but 1 thing they have in common is shape. Why are planets round? A planet’s gravity pulls equally from all sides, creating a sphere. See what other factors contribute: https://t.co/sorAsGaDlK pic.twitter.com/K2pjAnetNp

— NASA (@NASA) May 25, 2018