Geologically alive! Tectonic plates ride slowly on swirling rocky matter andmolten lava. This movement causes mountains and volcanoes. (2:212) Only 10 miles in diameter, it has created a meteor swarm from its debris 40 million miles long and 4 million miles wide. (2:221) 'Its last trip through the inner solar system was in 1986. It is believed to have made 300 'round trips'; each trip lasts 76 years. (2:222) 'In 1986 the European probe, Giotto, detected long carbon polymers of formal-dehyde molecules among its debris. (2:225) 'It has an Earth-like structure, with a rocky outer layer and a liquid metal-lic core. This planet rotates east to west in 244 days. (2:226) Soviet probes landed on its surface and found a main constituent of the sur-face to be Calcium Carbonate... a possible source of CO2 atmosphere. (2:227)This sole moon is large relative to its small cold planet. The two rotate around the combined gravitational center like a "dumbbell". (2:230) One of these may have devastated the remote Tunguska region of Siberia in 1908. It exploded with the force of a 12-megaton nuclear blast. (7:19) &A yellow-tan gaseous giant planet swept by winds of 1,000 mph. It has a set of thousands of rings of ice and rock 620,000 miles wide. (7:18) A huge planet... two and a half times as massive as all other planets combined! (7:18) This planet is circled by 16 moons and has fantastic curtains of lightning crackling above its hydrogen atmosphere. (7:19) A red ball of rock, its poles covered in ice, its arid landscape dotted withsand dunes, split by a canyon thousands of miles long... (7:19) This planet has a volcano 15 miles high and 250 miles wide! (7:19) Three fourths of its surface is covered with water. Its atmosphere is com- posed mainly of nitrogen and oxygen. (7:19) It is sustaining the only known life in the solar system. (7:19) A stifling planet, where temperatures soar to 900·F and clouds rain sulfuricacid. (6:19) This small planet is like a pockmarked cinder. Its year lasts only 88 Earth days... while its day lasts 59 Earth days. (6:19)(7:263) The German mathematician, Johannes Kepler determined that these bodies swingin elliptical orbits around the sun. (6:19) Flares from this body cause magnetic storms and the northern and southern light displays called... aurora borealis and aurora australis. (6:62) This star was formed about 4.6 billion years ago. It along with its planets coalesced from matter of earlier generations of exploded stars. (6:42) It is composed of 92.1% hydrogen atoms and 7.8% helium atoms; however the helium represents 25% of its mass. (6:73) It fuses hydrogen atoms together to make helium and enormous energy. The energy as heat and light radiates throughout the solar system. The Mariner 10 fly by of this inner planet in 1974 found it to be cratered and very much like our moon. (4:107-176) The perturbation of Uranus was correctly guessed to be caused by this large planet. Le Verrier calculated its location within one degree! (7:49) Percival Lowell incorrectly believed canals on this planet were proof of intelligent alien life. (7:63) This was the last planet of our solar system to be discovered. Clyde Tombaugh found it in 1930. (7:79) This dim & gloomy planet was named after the god of the underworld. The namewas first suggested by Venetia Burney, age ll. (7:84) Normally the outermost planet; yet, between 1979 and 1999 its orbit will take it closer to the sun than Neptune. (9:2A) The coldest planet appears to be a snowball of methane, water and mixed rocks. (9:2A) This pale bluish-green planet has a faint methane atmosphere. It was dis- covered in 1781 by Herschel. (7:89,90) Like Neptune, it's believed to have a rocky core covered with a mantle of liquid water, methane and ammonia. (3:46) It's the "tilted planet" because it rotates on its side (an axis tilted 98 degrees). (9:2A) Unlike its "twin planet," Neptune, it has an unusually large number of satellites (at least 15). (9:50,51) It's the largest moon circling Uranus. This moon has a jagged fault cutting across much of its cratered face. (9:52) This medium-sized moon of Uranus has large regions that look like "scoops ofmarble-fudge ice cream." (9:51) This moon of Uranus has unusual patterns on its surface which may have been caused by recent melting. (9:52) It is next to the largest Uranian moon, and it has the outermost orbit. It has a cold, dull, cratered surface. (7:267,3:51) This moon of Neptune has volcanic activity in the form of geysers. (3:52) This moon of Neptune is the size of our moon. It has large once-flooded craters and terrain like "cantaloupe skin." (3:53) This blue planet has a "Great Dark Spot" which is similar in size and move- ments with Jupiter's Red Spot. (3:45) This Martian moon looks like a "potato." Its longest dimension is less than ten miles long and 1.4 miles wide. (6:103) !This Martian moon is five miles longer than its sister Deimos. It has the predominate 6.2 mile wide Stickney Crater on its top. (6:103) In 1976, two Viking probes sampled the soil of this planet and could find noevidence of life. (6:103) According to a hypothesis, it's a dying star linked by gravitation to our sun. It nears our solar system every 26 million years. (6:154) (Possibly a huge body (Jupiter-like) which swings into our solar system every26,000,000 years and dislodges comets from the Oort Cloud. (6:154) (A 100,000,000,000 comets may be held in this area of our solar system. (6:148) %This group of comets and debris is loosely held in place by the sun's gravity. (6:148) %Named after the Dutch astronomer Jan H. Oort. It roughly covers an area 930 million to 1.86 billion miles from the sun. (6:148) %These bodies may have caused mass extinctions on the earth 11, 37, 66, and 91 million years ago. (6:154) &One or more of these bodies may have caused the great dinosaur die-off. Timelayered deposits of iridium around the world seem to support theory. (6:154)&More than 100 of these bodies loop the sun in very elongated orbits lasting 200 years or less. (6:149) &Over 1600 of these very small "planetoids" orbiting between Mars and Jupiterhave been individually tracked. (5:635) "Astraea, Pallas, Juno, Vesta, Piazzia, Gausia and Olbersia are all bodies within this group. (5:634) "It's the largest asteroid with a diameter one-fifth that of our moon--about 600 miles. (6:151) #The brightest asteroid, its albedo, or reflectivity, is nearly twice as muchas its companion asteroids. (5:635) $This planet's surface is hot enough to melt tin! (2:92) On July 20, 1969, the first human walked on this satellite. (2:95) This body is slowing the Earth's rotation; eventually it will lock Earth's rotation so that the same side of Earth will always face it. (2:125) This heavenly body has been blamed for both romantic and lunatic notions! It's the darkest of the Uranian moons. It has two unusually bright spots inside two large craters. (7:127) This Uranian moon was one of three named after characters in Shakespeare's plays. It was discovered in 1787 by William Herschel. (7:121) This Uranian moon discovered & named by Gerand Kuiper in 1948 after a char- acter in "The Tempest." It's the innermost major moon of Uranus. (7:12) This Uranian moon along with Umbriel were named from characters in AlexanderPoe's "The Rape of the Lock." It's the fourth largest moon of Uranus.(7:121)It's the Earth's closest companion. This nearly twin planet of Uranus has a "Giant Dark Spot" eerily reminiscentof Jupiter's Red Spot. (3:45) Amazingly this body (before it forms bright tails of ice and dust) is the darkest known object in the solar system. (3:51) 'This massive moon is the only major satellite that orbits in a direction opposite to the spin of its host planet. (3:52) This planet (one of the four gas giants) has intriguing ring arcs as well ascomplete--but dull--rings. (3:53) This Jovian moon has a surface "like a cracked billiard ball." It is scarredby numerous channels in a substantial icy crust. (8:35) Heavy volcanic activity makes this Jovian moon look like a hot cheese pizza!(8:35) By far the largest planet in our solar system. (7:264) One of the four inner planets which were all formed about 4.6 billion years ago. This one has atmospheric pressures 90 times those of Earth. (6:94) Although this planet is one of the brightest bodies in our sky, it is rarelyseen because of it's proximity to the sun. (6:89) This category of bodies is represented in our solar system by four rocky inner spheres, four gas giants, and a small, cold, outer world. (6:47) This Martian moon is only 13 miles long and spins around Mars three times each day. (7:265-269) This planet hosts a storm system, the Great Red Spot, which is 16,000 miles long and probably several hundreds of years old. (6:119) The largest Jovian moon as well as the largest moon in our solar system. It is bigger than Mercury and twice as big as Pluto! (7:263-269) Jupiter's gravitational pull actually stretches this inner moon. That con- tinual stretching and shrinking causes immense friction and heat. (6:123) This moon's largest volcano, Pele, spouts 10 tons of debris each second... spraying debris 175 miles into space! (6:122) Scientists speculate that this Jovian moon may have an ocean of liquid waterunderneath its icy crust. (6:122) This Jovian moon is the solar system's third largest--about the same size asMercury. It's geologically inactive with many old craters. (7:264, 6:122) This planet has a diameter nine times that of Earth, and it has an awesome array of tens of thousands of rings! (7:265, 6:124) Its outer rim of the main ring system is actually two rings braided togetherlike a loose rope braid. (6:124) At its equator, winds speeds are over 1,000 miles per hour--more than four times the speed of Jupiter's winds. (6:124) This moon's orbit lies in the middle of the 17 moon orbits of Saturn. It's aheavily cratered ice ball with a distinct giant impact crater. (6:126) This planet has the most moons. It has a liquid hydrogen and helium interiorand a very strong magnetic field. (6:124) Only the Jovian moon Ganymede is larger than this titanic moon which circlesSaturn. (7:130) It is unique for its reddish, smog-like atmosphere; no other moon has such athick atmosphere. (7:130) There is speculation that hydrocarbons in this moon's atmosphere might nurture some form of primitive life. (7:131) Ethane and methane may constitute a chemical ocean covering most of this moon's surface. (7:131) The outermost of the large icy Saturn satellites, it has one black side and the other side is brightly reflective. (7:131) It's the third planet from the sun. The second largest moon of Saturn. It has a bright, relatively smooth hemi- sphere facing the direction of orbit and a darker back side. (6:130) This medium size moon of Saturn has a companion moon--designated 1980S6-- which is locked in a Lagrangian orbit 60· in front of it. (6:130) Parallel ice ridges and grooves crisscross this largest Jovian moon. (6:137) This Jovian moon is the solar system's most heavily bombarded moon. It has concentric ridges radiating from a bright core crater. (6:137) This large moon of Neptune has a slowing orbit and within a few million years, Neptune's gravitational grasp will tear it apart. (6:132) It's the smaller moon of Neptune, and it has a very elongated elliptical orbit. (6:132) An astronaut observing Pluto from this moon would see the same face of Plutoas long as he cared to watch. (7:185) There are nine of these bodies known in our solar system.