Some astronomers think that the two gas-giants do not sport solid surfaces secreted beneath their immense and heavy gaseous atmospheres, although others suggest that the jumbo-size duo do, indeed, harbor relatively small cores of rocky-icy stuff. The two other large inhabitants of the outer limits of our Sun's family are Uranus and Neptune, which are both classified as ice-giants, because they harbor large icy cores secreted deep down beneath their heavy, dense gaseous atmospheres which, though very massive, are not nearly as heavy as the gaseous envelopes possessed by Jupiter and Saturn.
The influence of the moon on the Zodiac is a study in and of itself. When you are aware of your sun sign, you can use information about the cycles of the moon and the moon signs to determine the best time to make decisions or avoid certain activities. The moon signs are named the same as the Zodiac, but do not coincide with them.