Astronomy | Astrophysics Answers

The Moon has a radius of 1,738 km. Demonstrate that the Moon is just over ¼ the size of the Earth.

What is the sidereal orbit for Venus and what is its synodic period? Explain why is there a difference. Why is the synodic period for Neptune very close to the length of the Earth year?

For which planet is the sidereal year the longest? The shortest? Explain why.

What is the difference between a superior and inferior orbit? What are the planetary configurations and to which location does each refer?

Using Kepler’s three laws, Newton’s three laws of motion, and Newton’s Universal law of gravitation, explain how and why the planets orbit the Sun.

What is the difference between kilometers, AU, light-years and parsecs? Which measure or measures is/are best for describing distances to stars and why?

What is parallax and why is it important to the heliocentric model?

Compare and contrast the geocentric and heliocentric models. Why is the heliocentric model accepted today? What prevented the acceptance of the heliocentric model in the past?

Explain the contribution to astronomy that each of the following made: Copernicus, Brahe, Galileo, Kepler, Newton.

Explain the contribution to astronomy that each of the following made: Pythagoras, Aristarchus, Aristotle, Ptolemy.