Changes

Kepler's three laws of planetary motion were developed in the early 17th century by [[Johannes Kepler]].  Kepler developed the laws after studying the astronomical observations of [[Tycho Brahe]] for several years.  Kepler realized that the movement of the celestial bodies whose data Brahe had recorded did not fit a circular orbit, as was believed at the time.

Kepler's three laws of planetary motion were developed in the early 17th century by [[Johannes Kepler]].  Kepler developed the laws after studying the astronomical observations of [[Tycho Brahe]] for several years.  Kepler realized that the movement of the celestial bodies whose data Brahe had recorded did not fit a circular orbit, as was believed at the time.

Kepler's three laws of planetary motion are:

Kepler's three laws of planetary motion are:<br />

1.  Planets orbit the sun on [[ellipse|elliptical]] orbits with the sun occupying one of the foci of the ellipse.

1.  Planets orbit the sun on [[ellipse|elliptical]] orbits with the sun occupying one of the foci of the ellipse.