(astronomy) any of the nine large celestial bodies in the solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun; viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise direction

the smallest planet and the nearest to the sun

the second nearest planet to the sun; it is peculiar in that its rotation is slow and retrograde (in the opposite sense of the Earth and all other planets except Uranus); it is visible from Earth as an early `morning star' or an `evening star'

the smallest planet and the nearest to the sun

the second nearest planet to the sun; it is peculiar in that its rotation is slow and retrograde (in the opposite sense of the Earth and all other planets except Uranus); it is visible from Earth as an early `morning star' or an `evening star'