Classificação da Biblioteca do Congresso dos E.U.A. (LCC)QB659.M55

animals(255) asteroids(251) astrobiology(48) astrology(192) astrophysics(972) biology(133) black holes(305) children(688) children's(893) children's literature(140) climate(75) cosmology(1,010) cosmos(73) Creation(102) dark matter(97) early reader(114) earth(1,717) easy reader(141) education(131) educational(92) elementary(151) environment(230) exploration(229) fall(916) galaxies(325) galaxy(105) general science(88) geography(348) geology(602) Grade 2(123) gravity(88) green(71) history(1,063) history of science(398) hst(31) informational(722) informative(54) Jupiter(208) juvenile(288) juvenile literature(80) juvenile non-fiction(190) kids(250) leaves(204) light(82) lunar(66) Mars(1,034) Mars (Planet)(65) meteors(186) moon(1,742) nasa(340) natural science(165) natural world(44) nature(1,036) observation(45) outer space(901) photographs(271) photography(477) physics/astronomy(27) picture book(1,829) planet(209) planetology(35) planets(3,720) Pluto(241) popular science(366) preschool(79) primary(97) quasars(29) reader(85) reference(661) relativity(44) rockets(38) school(166) science(16,858) science and technology(77) science fiction(429) science nonfiction(164) snow(127) solar system(4,100) space exploration(633) space flight(142) spacecraft(40) spring(604) stars(1,734) summer(359) time(78) universe(468) volcanoes(101) weather(992) winter(743)