Our solar system
In the introduction he writes:
The Nine Planets is a collection of information about our Solar System intended for a general audience with little technical background. No special expertise or knowledge is needed; all technical and astronomical terms and proper names are defined in the glossary. The bulk of this material should be familiar to planetary scientists and astronomers but they may find a few interesting tidbits, too.Well! I think Bill Arnett has done a nice job! Perhaps I should adopt his way and spirit, so I can make also a serious website with serious and complete contents about one thing I like.