Kepler developed the Laws of Planetary motion, which include the orbits of planets being elliptical.
Kepler is the answer. Try looking him up on wikipedia. Its right there in the text. :)
Johannes Kepler
It was Kepler who discovered that the planets orbits are elliptical.
Johannes Kepler corrected Copernicus by stating that the planets revolve around the Sun in elliptical orbits, not in circular orbits. That became one of Kepler's laws of planetary motion. Altogether, Kepler formulated three "laws of planetary motion" based on the heliocentric model of Copernicus.
No, all the planetary orbits are elliptical.
As an elliptical orbit is any orbit that isn't perfectly circular, everything has an elliptical orbit. The planets Mercury and Pluto have the most elliptical orbits of the planets, and are easily seen to be oval shaped. Comets also have highly elliptical orbits.
Johannes Kepler
Planetary orbits are usually taught to be circular. However, they are truly more elliptical (oval shaped).
Planetary orbits that are elliptical will have a greater focus.
It would be more accurate to say that the mathematical study of the nature of an ellipse, showing that it can result from cutting through a cone in a particular way, helps to understand the nature of elliptical planetary orbits, but it does not prove that planets have elliptical orbits. It requires actual astronomical observation of planetary orbits to determine what kind of orbits they are.
Yes
Kepler's first law of planetary motion published in 1618 says that the planets travel in elliptical orbits with the Sun at one focus. Newton's law of gravity and other work he did explains how the Sun's gravity produces ellpitical orbits.
It was Kepler who discovered that the planets orbits are elliptical.
17th century astronomer Johannes Kepler discovered the elliptical shape of the planets' orbits around the Sun, which he described in his first law of planetary motion. Newton later explained this in his law of universal gravitation.
Johannes Kepler corrected Copernicus by stating that the planets revolve around the Sun in elliptical orbits, not in circular orbits. That became one of Kepler's laws of planetary motion. Altogether, Kepler formulated three "laws of planetary motion" based on the heliocentric model of Copernicus.
Elliptical orbits of the planets around the sun actually match what we observe. Newton's Theory of Universal Gravitation states that planets will move around the sun in elliptical orbits.
No, all the planetary orbits are elliptical.
Most planetary orbits are elliptical.