Setting

is to understand the evidence that leads us to what we believe.

For today, however, I am relaxing this stringent criterion.

Today�s class is a tour of our current understanding of the

solar system. It is without a doubt true that some aspects

of this understanding will ultimately prove to be false.

However, there is no way that I could treat critically all the

observations and reasoning that lie behind all the many

conclusions I will describe today.

For this reason, today�s class should be treated as

entertainment. The topics discussed will not be

covered on exams.