Summer vacation destinations for Seneca, too, realized that comets were objects orbiting in the highest heavens that were not confined to the zodiac, in contrast to the planets. Whereas the orbits of the planets are narrowly inclined to the ecliptic plane and are all prograde i.e., counterclockwise from the vantage point of Earth’s north pole, cometary orbital planes can be inclined at any angle to the ecliptic and hence be either prograde or retrograde clockwise. In addition, comet orbital planes may be oriented at any angle, and the orbit itself may be positioned in any direction within the plane. How long a comet takes to complete one revolution and how far away from the Sun it goes depend on the comet’s eccentricity the shape of its orbit and how close it gets to the Sun at perihelion. As regards eccentricity, while some comets, like the major planets, have almost circular orbits, most comets have orbits that are elongated ovals ellipses, and some have evolved into orbits that are hyperbolic, meaning that they may never return to the inner solar system fig. Summer vacation destinations 2016.