Bing found the following results
Planet - Wikipedia
Planets - NASA Science
Planet | Definition, Characteristics, & Facts | Britannica
All About the Planets | NASA Space Place – NASA Science for Kids
What is a Planet? - NASA Science
What Is a Planet? | NASA Space Place – NASA Science for Kids
planet - National Geographic Society
What is a Planet? | Planets – NASA Solar System Exploration
In Depth | Our Solar System – NASA Solar System Exploration
What is a Planet? - NASA Science