When is a planet not a planet? Dwarf planets orbit the sun, are solid bodies, and are not moons. But they are not considered regular planets. Learn more about these spherical oddities and why Pluto is still hotly debated today.
From planets and comets to sunspots and spacewalks, there's so much to know about space! Show Me Space has more than 100 facts and definitions about our solar system and beyond.
There's no air in space. But robots don't care! Learn more about how these mechanical robonauts can help us understand more about the solar system in which we live.