Need some fast facts about our solar system? Your search has ended! The perfect reference source for looking up planets, stars, constellations, and even the history of space travel. Find: ? Our Solar System, including Sun, Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, each with Distance from the Sun, Radius, Volume, Mass, Density, Surface Gravity, Escape Velocity, Sidereal Rotation Period, Sidereal Orbit Period, Mean Orbit Velocity, Orbit Eccentricity, Orbit Inclination, Equatorial Inclination, Mean Surface Temperature, Major Atmospheric Constituents, and Natural Satellites ? Missions In Space, including Past Missions, Present Missions, Future Missions, Mercury Manned Missions, Gemini Manned Missions, Apollo Manned Missions, Skylab Manned Missions, ASTP Manned Missions, and Shuttle Manned Missions ? Astronomy In History, including Ancient Times, Astronomers of Greece, Pioneers, and Terms ? Stars & Constellations, including 26 Brightest Stars, 15 Closest Stars, List of Constellations, Viewing Constellations, Evolution/Types of Stars, and Spectral Types of Stars Organized in a three-layer subject hierarchy and in an index in remarkably small files, so navigation on your handheld is fast and easy.