Orbits and Gravity (Astronomy)

Recall cards on how the motions of the planets were measured and finally explained. Tycho Brahe's 20 years of observations and Kepler's three laws of planetary motion: elliptical orbits, foci and eccentricity, the law of equal areas, and P squared = a cubed. Newton's synthesis: his three laws of motion, momentum, mass, velocity, acceleration, density, and angular momentum. The universal law of gravitation, the inverse-square force, the gravitational constant, and Newton's mass-bearing form of Kepler's third law. Orbits in the solar system: perihelion and aphelion, the eight planets, the asteroid belt, and comets. Satellites and spacecraft: circular and escape speeds, orbital decay, and gravity assists (Voyager 2). Finally, gravity with many bodies: perturbations and the prediction and discovery of Neptune that confirmed Newton's laws.