This week's topic is the terrestrial planets, and how they
might be understood in terms of fundamental principles of comparative
planetology. How do the fundamental features of the planets, their size,
mass, composition, distance from the Sun, affect their subsequent evolution.
We will compare the interiors, surface features and atmospheres of the Moon,
Mercury, Mars and Venus with Earth to find out why Earth's surface might be unique
in harboring life. We'll also take a short look at the outer planets.