... Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. ... Looking Down on Saturn . ... This picture of Saturn could not have been taken from Earth. No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn's rings. Since Earth is much closer to the Sun than Saturn, only the day side of the planet is visible from the Earth. The Clouds of Jupiter . ... Globular Cluster 47 Tucanae . ...