Changes

The '''orbits''' of [[planet]]s observable in [[Kepler]]'s times were very circular. [[Comet]]s, on the other hand, have highly [[eccentric]] orbits with only one [[focal point]] inside the [[Sun]].

Scientists assumed that the '''orbits''' of [[planet]]s observable in [[Kepler]]'s times were very circular. Kepler was the first to propose that the planets' orbits were elliptical, thus improving the accuracy and prediction-value of the heliocentric view of the solar system. [[Comet]]s, on the other hand, have highly [[eccentric]] orbits with only one [[focal point]] inside the [[Sun]].

The orbit of the [[Moon]] is nearly a perfect circle, but due to its high relative weight the center of its orbit is actually closer to the Earth's surface than to than it is to the exact center of the Earth.

The orbit of the [[Moon]] is nearly a perfect circle, but due to its high relative weight the center of its orbit is actually closer to the Earth's surface than to than it is to the exact center of the Earth.

[[category:physics]]

[[category:physics]]