Kids Astronomy

Welcome

Stars and nebula in the Small Magellanic Cloud (SMC). The SMC is a satellite galaxy to our own Milky Way galaxy.

Welcome to the world of Kid's Astronomy. The word "astronomy" comes from ancient Greek "astro-" (star) and "-nomos" (arranger). Here, you will not be moving stars about (arranging them), but you will be learning about them. And there is more about astronomy than just stars. The subject covers nebulas, galaxies, quasars, black holes, brown dwarfs, planets, asteroids, comets and more.

Stars are balls of gas, but unlike a balloon filled with air, stars are very, very big and very, very heavy. Our sun is a star — an ordinary G-type dwarf, but the gas in our sun weighs more than all the mountains on Earth. In fact, it weighs many thousands of times more than Earth itself.

Planets are much smaller than stars — much lighter (less massive). Some planets, like Earth, are mostly rock and metal with some or only very little gas. And that is a good thing. We need a solid surface on which to build our houses and cities, for riding our bicycles and for placing our desks and computers.

Create Your Own Planet

Scientists have found many planets beyond the Solar system, circling other stars, but most of those are like Jupiter — mostly gas. Earth-like planets — those with solid surfaces — are perhaps the most fascinating kind of planets. Find out how to make your own planet. Here you get to decide what kind of star, how close your planet is to its sun, and much more.