Kepler's First Law Demo

A satellite follows an ellipse with Earth at one focus, not at the center of the ellipse.

Increase eccentricity to see Earth move away from the ellipse center. ellipse center Earth at one focus other focus satellite distance changes First law: the orbit is an ellipse and Earth is located at one focus.
Eccentricity0.55
Animation speed1.0x

Concept: For a circular orbit, both foci and the center coincide. As eccentricity increases, the ellipse becomes more stretched and Earth is clearly at a focus, not at the center.

OrbitDistance to satellite