Saturn: The sixth planet in order from the sun. It is one of the five outer planets of the solar system. Its twelve natural satellites include Phoebe and Titan.Spacecraft: Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)Extraterrestrial Environment: The environment outside the earth or its atmosphere. The environment may refer to a closed cabin (such as a space shuttle or space station) or to space itself, the moon, or other planets.Atmosphere: The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)Ice: The solid substance formed by the FREEZING of water.Necrobiotic Xanthogranuloma: A cutaneous necrobiotic disorder characterized by firm, yellow plaques or nodules, often in a periorbital distribution. It is often accompanied by an elevated ERYTHROCYTE SEDIMENTATION RATE; LEUKOPENIA; and MONOCLONAL GAMMOPATHY (IgG-kappa type) and systemic involvement.Moon: The natural satellite of the planet Earth. It includes the lunar cycles or phases, the lunar month, lunar landscapes, geography, and soil.Jupiter: The fifth planet in order from the sun. It is one of the five outer planets of the solar system. Its sixteen natural satellites include Callisto, Europa, Ganymede, and Io.Specific Gravity: The ratio of the density of a material to the density of some standard material, such as water or air, at a specified temperature.Smog: A mixture of smoke and fog polluting the atmosphere. (Dorland, 27th ed)Hydrocarbons, Acyclic: Organic compounds composed exclusively of carbon and hydrogen where no carbon atoms join to form a ring structure.Earth (Planet): Planet that is the third in order from the sun. It is one of the four inner or terrestrial planets of the SOLAR SYSTEM.Planets: Celestial bodies orbiting around the sun or other stars.Telescopes: Instruments used to observe distant objects.Space Flight: Travel beyond the earth's atmosphere.Astronauts: Members of spacecraft crew including those who travel in space, and those in training for space flight. (From Webster, 10th ed; Jane's Aerospace Dictionary, 3d ed)Science: The study of natural phenomena by observation, measurement, and experimentation.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Sleep: A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.Dance Therapy: The use of dancing for therapeutic purposes.Blogging: Using an INTERNET based personal journal which may consist of reflections, comments, and often hyperlinks.Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.Firearms: Small-arms weapons, including handguns, pistols, revolvers, rifles, shotguns, etc.Evolution, Planetary: Creation and development of bodies within solar systems, includes study of early planetary geology.Pluto: The ninth planet in order from the sun. It is one of the five outer planets of the solar system. Its only natural satellite is Charon.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.United States National Aeronautics and Space Administration: An independent Federal agency established in 1958. It conducts research for the solution of problems of flight within and outside the Earth's atmosphere and develops, constructs, tests, and operates aeronautical and space vehicles. (From U.S. Government Manual, 1993)Miniaturization: The design or construction of objects greatly reduced in scale.Automatic Data Processing: Data processing largely performed by automatic means.Quantum Theory: The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.Organ Preservation Solutions: Solutions used to store organs and minimize tissue damage, particularly while awaiting implantation.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Memory, Short-Term: Remembrance of information for a few seconds to hours.Tissue Preservation: The process by which a tissue or aggregate of cells is kept alive outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Steroids: A group of polycyclic compounds closely related biochemically to TERPENES. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (STEROLS), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. (From Hawley's Condensed Chemical Dictionary, 11th ed)New YorkSpin Labels: Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)New York CitySolar System: The group of celestial bodies, including the EARTH, orbiting around and gravitationally bound by the sun. It includes eight planets, one minor planet, and 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as MINOR PLANETS (asteroids) and METEOROIDS. (From Academic American Encyclopedia, 1983)Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Tail