Study Guide for Astronomy & Astrophysics I Exam 1 (Fall 2017)
 Be familiar with Galileo's observational evidence for the heliocentric model of the solar system.

Make sure you understand Kepler's Third Law in all of its forms, what the
constant k = 4p^{2}/G(m_{1}
+ m_{2}), and what the third law implies for relative speeds of planets with distance.
 Be able to identify the key orbital positions of planets (conjunctions, oppositions, greatest elongations) and what planets would look like as viewed from Earth.

Review ellipses,
relationships between semimajor axis, semiminor axis, eccentricity, and perihelion/aphelion
distances. Keep in mind that you can draw an ellipse with a string and two pins.
 Review the four conic sections, how they relate to orbit types, and what eccentricities and energies correspond to them.
 Be able to explain how planets behave in their orbits, especially near perihelion and aphelion, in terms of distance, speed/velocity, angular momentum and energy.
 Review the concepts and equations of plate scale and angular size of features seen with a telescope/camera.

Review the relation between synodic and sidereal periods.
 Be familiar with effective potential energy and the role of angular momentum.