johannes kepler developed most of our current understanding of planetary motion.
johannes kepler developed most of our current understanding of planetary motion.
who developed most of our current understanding of planetary motion?
johannes kepler
the modern understanding of planetary motion arose from the combined efforts of astronomer tycho brahe and physicist johannes kepler in the 16th century. tycho is credited with extremely accurate measurements of planetary motions, from which kepler was able to derive his laws of planetary motion. according to these laws, planets move on ellipses (not epicycles) about the sun (not the earth). kepler's second and third laws make specific quantitative predictions: planets sweep out equal areas in equal time, and the square of their orbital periods equals a fixed constant times the cube of their semi-major axis. subsequent observations of the planetary orbits showed that the long axis of the ellipse (the so-called "line of apsides") rotates gradually with time; this rotation is known as "apsidal precession". the apses of an orbit are the points at which the orbiting body is closest or furthest away from the attracting center; for planets orbiting the sun, the apses correspond to the perihelion (closest) and aphelion (furthest).
newton's theorem of revolving orbits
kepler's laws of planetary motion









































in astronomy, kepler's laws of planetary motion are three scientific laws describing the motion of planets around the sun.









































bullet::::1. the orbit of a planet is an ellipse with the sun at one of the two foci.









































bullet::::2. a line segment joining a planet and the sun sweeps out equal areas during equal intervals of time.









































bullet::::3. the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.
kepler's laws of planetary motion