Question

What is Kepler's First Law of Planetary Motion?

1) Planets move in elliptical orbits around the sun
2) The square of the period of revolution of a planet is proportional to the cube of its average distance from the sun
3) Planets move in circular orbits around the sun
4) The speed of a planet is constant throughout its orbit

Answer 1

Kepler's First Law of Planetary Motion indicates that planets orbit the Sun in elliptical paths, with the Sun at one focus of the ellipse. Thus, the option 1 is the correct answer.

Step-by-step explanation:

Kepler's First Law of Planetary Motion states that planets move in elliptical orbits around the sun, with the Sun being located at one of the foci of the ellipse. This law challenged the long-held belief that planets moved in circular orbits. An ellipse is a shape for which the sum of the distances from each point on the curve to two distinct focal points is constant. Thus, the orbit of each planet is not a perfect circle, but an oval shape, which can vary from nearly circular to quite elongated.