Elliptical
Copernicus
Nicolas Copernicus
NINE!!
galileo galilei
around the sun, not the earth.
Nicolaus Copernicus discovered why planets stay in orbit when he found that the planets revolve around the sun. He is credited with starting the Scientific Revolution through this discovery.
The surprising thing to me is how MANY extra-solar planets have been discovered. Considering the limitations of the Kepler Space Telescope's design, this indicates that there may be planets around a majority of the stars.
He discovered that the planets revolved around the sun instead of the planets & the sun revolving around Earth.
copernicus
He discovered that the Earth and all of the planets revolve around the Sun.
42.068
Johannes Kepler discovered that planet orbits were elliptical and not circular.