The thirteen planets. National Geographic Live! - Solar System Exploration: 50 Years and Counting. The Solar System HD. Largest Star Ever Discovered. Amazing video: Planets viewed from Earth as if they were at the distance of our moon. The Universe in 3D: Planet & Star Size Comparison - Version 3 [1080p] Planet/Star Size - Our Solar System & The Other Stars. Why Isn't Pluto a Planet Any More? A Traveler's Guide to the Planets. So you think you're big?