principal planets
61Asteroide troyano — Localización de los asteroides troyanos. También se muestra el cinturón principal. Los asteroides troyanos son asteroides que comparten órbita con un …
62Hindu chronology — The subject of Hindu chronology divides naturally into three parts: the calendar, the eras, and other reckonings. The Calendar The Hindus have had, from very ancient times, the system of lunisolar cycles, made by the combination of solar years,… …
63Edward Wright (mathematician) — For the 20th century mathematician, see Edward Maitland Wright. Edward Wright Title page of the first edition of Wright s Certaine Errors in Navigation (1599) …
64chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
65Rotation — This article is about movement of a physical body. For other uses, see Rotation (disambiguation). A polyhedron resembling a sphere rotating around an axis. A rotation is a circular movement of an object around a center (or point) of rotation. A… …
66MESSENGER — This article is about the NASA space mission. For other uses, see Messenger. MESSENGER Artist s rendering of MESSENGER orbiting Mercury. Operator NASA / APL Major contractors APL …
67EPOXI — Infobox Spacecraft Name = EPOXI Caption = Illustration of the Deep Impact space probe used on EPOXI mission. Organization = NASA Major Contractors = Ball Aerospace Technologies Corp., JPL Mission Type = Flyby Flyby off = Comet Boethin Launch =… …
68Solar System — This article is about the Sun and its planetary system. For other systems, see planetary system and star system. For a list of physical and orbital statistics for the Solar System s largest bodies, see List of gravitationally rounded objects of… …
69Definition of planet — Photograph of the crescent planet Neptune (top) and its moon Triton (center) …
70Gaia hypothesis — The study of planetary habitability is partly based upon extrapolation from knowledge of the Earth s conditions, as the Earth is the only planet currently known to harbour life. The Gaia hypothesis, also known as Gaia theory or Gaia principle,… …
