There is a bizarre rocky landscape, well hidden from our prying eyes, in the secretive shadows under the oceans of our Earth. Here, in this strange and alien domain, it is always as dark as midnight. Thin, tall towers of craggy rock emit billows of black smoke from their peaks, while all around the towers stand a weird, wavy multitude of red-and-white, tube-like organisms--that have no eyes, no intestines, and no mouth. These 3-foot-long tubeworms derive their energy from Earth itself, and not from the light of our nearby Sun--a feat that most biologists did not believe possible until these wormish creatures were discovered back in 2001. The extremely hot, superheated black water, billowing out from the hydrothermal vents erupting on Earth's seafloor, provides high-energy chemicals that sustain the tubeworms, as well as other weird organisms that apparently thrive in this very improbable habitat.
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.
"Titan is a very active moon. We already know that about its geology and exotic hydrocarbon cycle. Now we can add another analogy with Earth and Mars: the active dust cycle, in which organic dust can be raised from large dune fields around Titan's equator," Dr. Sebastien Rodriguez explained in a September 24, 2018 NASA Jet Propulsion Laboratory (JPL) Press Release. Dr. Rodriguez is an astronomer at the Universite Paris Diderot, France, and the paper's lead author. The JPL is in Pasadena, California.