Orbits Revisited

• Shapes and conic sections
• Energetics: bound vs unbound orbits
• Escape speed

The Two-Body Problem

• Center of mass
• binary system orbits

Testing Newton's Gravity

• source of Uranus orbit perturbations
  kudos to Le Verrier
• binary stars
• globular star clusters, e.g., 47 Tuc, Omega Cen

Geocentrism vs Heliocentrism: Lessons

• wagers