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.
In the Eastern world, such as in China and India, the moon is actually the primary consideration in studies of astrology. The moon signs and cycles are used to determine the best time for activities, and is a part of daily life. This may seem backward to some, but actually results in more accurate predictions in many cases than Western astrology can ascertain.
These icy moon-worlds are the next important step in the scientific quest for the Holy Grail of life beyond our own planet. It is a strange era in human history. Astronomers have collected large amounts of data revealing bewitching clues that habitable ocean moon-worlds may be out there, within the family of our very own Star. Humanity is poised at the beginning of a new era. Sophisticated new technology might very soon answer the profound, and very ancient question, "Are we alone?"