Here are three easy ways to say the same thing. Read each one and pick the one you like best:
Space is very big and full of stars and planets. Our solar system is inside space. The Sun sits in the middle, and eight planets — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune — go around it.
Space is enormous and sparkles with stars and lots of planets. One part of space is our solar system. The Sun stays in the center, and the eight planets circle around it: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Think of space as a huge playground with stars and planets everywhere. Our solar system is one corner of that playground. The Sun is in the middle, and eight planets — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune — move around it like friends walking in a circle.
Tip: Try saying each sentence out loud to see which one sounds best to you!