Exam 3: Motion of Astronomical Bodies

You find a moon orbiting a planet and you measure the distance between the moon and the planet once a night over the course of a few weeks. Its behavior is shown in the figure below where the time shown is the time since your first observation. What is this moon's orbital period?

Astronomers argued that the heliocentric model of the Solar System was simpler than the geocentric model, based on:

Kepler's second law says that if a planet is in an elliptical orbit around a star, then the planet moves fastest when the planet is:

Planets with circular orbits travel at the same speed at all points in their orbits, whereas planets with elliptical orbits change their speeds at different points in their orbits.

Who was the first notable historical figure to argue that the Earth orbits the Sun? Name two other people that were instrumental in arguing for the heliocentric model.

Explain how the synodic and sidereal periods of a planet are defined. Why are they not the same? Explain how they are related to one another.

An empirical science is one that is based on:

Assume that at sunset today, Jupiter appears to be 20 degrees away from the Sun. If the sidereal period of Jupiter is 12 years, when will it next appear exactly in this same position relative to the Sun?

The fact that Kepler's heliocentric model of the Solar System predicted _________ more easily and accurately than the geocentric model is an illustration of how scientific theories evolve by the scientific method.

Even though they move at faster average speeds, the outer planets in the Solar System have longer periods than the inner planets.

If the Sun is located at one focus of Earth's elliptical orbit, what is at the other focus?