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What you will learn in Planets and Planetary Science
1. The rocky worlds
Mercury, Venus, Earth and Mars are small, dense and made of rock and metal. Plotting them beside the giants shows the split before anyone names it.
2. The giants
The four outer planets are enormous and, by the standards of rock, barely there at all — but calling them gas invites a picture that is wrong in a specific way.
3. Atmospheres
A world's temperature starts as arithmetic: how much light arrives, and how much it reflects away. Everything else is a correction to that.
4. Venus and the greenhouse effect
Venus is not the hottest planet because it is the closest. It is not the closest. The gap between what the arithmetic predicts and what we measure is over five hundred degrees.
5. Reading a planet's surface
Almost every famous picture of a planet is a measurement that has been rendered, not a photograph. Knowing which is which is the difference between looking and seeing.
6. Magnetic fields
Earth holds the solar wind off ten of its own radii away and wears two rings of aurora for it. Mars has no field to do either, and Jupiter's would look wider than the Sun in our sky if it glowed.
7. Days, years and tilts
A planet's day has nothing to do with its year, two planets spin backwards, and one lies on its side. Rotation is where the Solar System stops looking tidy.
8. Comparative planetology
The method that makes planetary science a science: not eight separate descriptions, but one set of properties measured eight times, so the patterns and the exceptions both stand out.