PLANETS & MOONS EXTRASOLAR PLANETS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site giant planet A planet that is much larger and more massive than Earth. In practical terms, this probably means that all giant planets are gas giants, since it is hard to see how an exclusively rock-metal planet could acquire enough material in a protoplanetary nebula to take on such huge proportions. Related categories    • PLANETS AND MOONS    • EXTRASOLAR PLANETS AND SUBSTELLAR OBJECTS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP