Kepler's Laws Diagram | Quizlet

Kepler's First Law

The orbit of every planet is an ellipse with the Sun at one of the two foci.

Kepler's Second Law

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

Kepler's Third Law

The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. (a squared = p cubed)

Aphelion

farthest distance away from the foci of a body rotating around the foci. Earth to sun = ~152 million km.

Perihelion

closest distance away from the foci of a body rotating around the foci. Earth to sun = ~147 million km.

Astronomical Unit (AU)

the distance from the earth to the sun. ~150 million km

Orbit

The curved path of a celestial object about a point in space

Period

The time that it takes a complete cycle

Major Axis

Longest Line (top to bottom in vertical, left to right in horizontal, in this example V1 to V2)

Minor Axis

Shortest Line (left to right in vertical, top to bottom in horizontal, in this example P1 to P2)

Semi Major Axis

Half of the Major Axis (C to one of the Vs)

Semi Minor Axis

Half of the Minor Axis (C to one of the Ps)

Vertex

Both end points of the Major Axis (V1, V2)

TERM

Co vertex

DEFINITION

Both endpoints of the Minor Axis (P1, P2)

Focus

Points near the vertex (F1, F2)

eccentricity of an ellipse

the ratio of the distance between the foci to the major axis (the ration of F1 to F2 and V1 to V2)

TERM

Foci

DEFINITION

two points inside the ellipse that characterize its shape and curvature

TERM

vertices

DEFINITION

endpoints of the major axis

TERM

center

DEFINITION

the intersection of the major and minor axes