Glossaire beginning with K

Kepler's laws

1. The orbits of planets or comets are ellipses with the Sun at one focus, or sometimes in the case of comets paraboles for which the Sun is at the focus.

2. The line segment that unites the planet or comet to the Sun sweeps out equal areas in equal times.

3. The square of the orbital period of a planet or comet is proportional to the cube of the semi-major axis of its orbit.

Kuiper Belt
Region of the Solar system where there are icy objects like Pluto and comets, between 30 and 55 astronomical units from the Sun.