General orientation to the Solar System I

The Scientific Method


Froderick Frankenstein
What is science?

Despite the impression you may get from media and intro-level science courses, science is absolutely not a body of knowledge. Rather it is the method of inquiry that has yielded that knowledge.

The guiding principle of scientific inquiry was perhaps best summed up by a non-scientist, the novelist Arthur Conan Doyle, who placed into the mouth of his character Sherlock Holmes these words:

"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."

The modern practice of science is based on the hypothetico-deductive method of science (a.k.a. the "scientific method"), a method that employs that principle, with a little twist.

Key components of the hypothetico-deductive method of science:

Two ways to overturn a theory:

Introducing the Solar System


From The Solstice Blog

Orbits of the planets (and Pluto) to scale. Not shown are the minor bodies (asteroids and comets) and the icy worlds of the Kuiper Belt (except Pluto). Key concepts:


The scale of the Solar System: On a 1/10 billion scale:

For fun, check out the Smithsonian's 1/10 billion scale Model Solar System on the National Mall


From The European Southern Observatory
The Sun: The primary body of the Solar System. (In ultraviolet light - right) Some basic attributes:


The Sun and Planets to scale


From NASA

Solar System bodies: We see four general classes (!) distinguished by mass and composition:


Be careful! This taxonomy is crude and imperfect. Some categories are clearly arbitrary associations of unrelated things (minor bodies) and some planetary bodies don't fit neatly into any of them (E.G. Europa).




Key concepts and vocabulary. Understand these or you're toast:
Additional reading: