In Western astrology, planets are objects that move through the sky. The planets most used in astrology are the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Chiron, and the asteroids. Earth is not considered a planet, as Western astrology is geocentric and has the Earth as a point of reference around which the planets appear to move. Since, from this viewpoint, the Earth doesn't move in the sky, it's not considered.