Sentence:  The radio radiation of the sun which is reflected from the moon and <WSD>planets</WSD> should be negligible compared with their thermal emission at centimeter wave lengths , except possibly at times of exceptional outbursts of solar radio noise . 
Meaning of the word marked with <WSD> tags:  (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