Front

What is at the middle of a Heliocentric system?

Back

Sun

Front

When a planet or moon travels once fully in its orbit around a largest celestial body, it is a(n):

Back

Revolution

Front

What is true about the area between points A, B and the Sun, and the area between points H, I and the Sun?

Back

Both areas are equal in size

Front

Ptolemy's model of the universe:

Back

Explained retrograde motion of planets with epicycles

Front

What is at the middle of a Geocentric system?

Back

Earth

Front

What is Kepler's First Law of Planetary Motion?

Back

Planets move in elliptical orbits with the Sun at one focus.

Front

What does Kepler's Second Law state?

Back

A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.

Front

What is Kepler's Third Law of Planetary Motion?

Back

The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

Front

Define 'Elliptical Orbit'.

Back

An orbit that is shaped like an ellipse, with two foci, one of which is occupied by the Sun.

Front

What is 'Retrograde Motion'?

Back

The apparent motion of a planet in the opposite direction to that of other bodies within its system.