What Is a Planet? A Beginner's Guide Introduction Have you ever looked at the night sky and wondered what planets are? A planet is one of the most fascinating objects in space. From the rocky surface of Mars to the giant storms of Jupiter, planets come in many shapes and sizes. Understanding what a planet is helps us learn more about our Solar System and the universe beyond. Scientists have studied planets for centuries, and modern technology has revealed thousands of planets across the galaxy. In this beginner's guide, we will explore what planets are, how they form, the different types of planets, and some amazing facts about them. What Is a Planet? A planet is a celestial body that orbits a star, has enough gravity to become nearly round in shape, and has cleared its orbital neighborhood of other large objects. In our Solar System, all planets orbit the Sun. There are currently eight officially recognized planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, a...