nine planets

The Nine Planets

A Multimedia Tour of the Solar System

by Bill Arnett

Bill's site map


The New Solar System

Summarizes what we've learned from interplanetary explorations in the last 25 years. My primary reference for The Nine Planets.

T. Rex and the Crater of Doom

The story of the discovery of the impact crater that doomed the dinosaurs. Nice description of how science works in the real world.

Encyclopedia of the Solar System

A more scholarly introduction to planetary science for those who want to dig a little deeper.

The Compact NASA Atlas of the Solar System

This 'road map' of the solar system contains lots of maps and data as well as photos.

Bad Astronomy

The truth is out there; so is a lot of baloney. Here's the straight story on many popular urban legends, myths and misconceptions. Great fun, too!

Build Your Own Telescope

Want to see the planets for yourself? It's actually pretty easy to make a simple but powerful telescope. Here's how.

This website is an overview of the history, mythology, and current scientific knowledge of each planet and the major moons in our solar system. Each page has my text and NASA's images, some have sounds and movies, most provide references to additional related information.

All nine planets can be seen with a small telescope; all but Pluto can be seen with binoculars. And large observatories continue to provide much useful information. But the possibility of getting up close with interplanetary spacecraft has revolutionized planetary science. Very little of this site would have been possible without the space program.

Nevertheless, there's a lot that you can see with very modest equipment or even with just your own eyes. Past generations of people found beauty and a sense of wonder contemplating the night sky. Today's scientific knowledge further enhances and deepens that experience. And you can share in it by simply going out in the evening and looking up.

An object bigger than Pluto has been found in the outer solar system by astronmers Mike Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University). It is possible, perhaps likely, that it will eventually be considered to be our solar system's tenth planet. For more info, see NASA's press release and the discoverer's web site. Its temporary designation is 2003UB313; an official name will be given in due course (more). Brown et al have now also spotted a moon orbiting this object.

Meanwhile, the New Horizons mission to Pluto and beyond was launched successfully on 2006 Jan 19 and should reach Pluto in July 2015.

The most recent version of this site can be found at

Our knowledge of our solar system is extensive. But it is far from complete. Some of the worlds have never even been photographed up close. The Nine Planets is an overview of what we know today. We are still exploring. Much more is still to come:

We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.
-- T. S. Eliot

nine planets ... Intro/FAQ ... Overview ... Sun ... Data
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Copyright © 1994-2006 by William A. Arnett; last updated: 2006 Jan 19
The most recent version of this site can be found at