Keplers Laws

Front

What is Kepler's First Law?

Back

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

Front

What does the term 'eccentricity' refer to in an orbit?

Back

Eccentricity measures the deviation of an orbit from being circular; a value of 0 indicates a perfect circle.

Front

What is the shape of a planet's orbit according to Kepler's Laws?

Back

An ellipse.

Front

What is Kepler's Second Law?

Back

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

Front

What happens to a planet's speed as it gets closer to the Sun?

Back

The planet moves faster.

Front

What happens to a planet's speed when it is farthest from the Sun?

Back

The planet moves slower.

Front

What is the focus in an elliptical orbit?

Back

One of the two fixed points in an ellipse; the Sun is located at one of these foci.

Front

What is perihelion?

Back

The point in the orbit of a planet where it is closest to the Sun.

Front

What is aphelion?

Back

The point in the orbit of a planet where it is farthest from the Sun.

Front

How does the area swept by a planet relate to its distance from the Sun?

Back

The area swept is constant over equal time intervals, regardless of the planet's distance from the Sun.