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Astronomy Reference Libraries

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Ursa Major big bear Constellation
2004-10-19 04:45:44

Ursa Major (big bear) Constellation -- Location: Northern Hemisphere; Coordinates: Right Ascension: 11h; Declination: +50; Source: Greek, Roman, and Native American mythology The constellation name, Ursa Major, means Big Bear. The "bear" association has its origins in two major civilizations which saw two very different bears in the sky. The Greeks who named this constellation (later...

Tucana Constellation
2004-10-19 04:45:44

Tucana Constellation -- Location: Southern Hemisphere (polar region); Coordinates: Right Ascension: 24h; Declination: -65; Source: 17th century Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman, with astronomer Johann Bayer Tucana is named for the Toucan, a brightly colored South American bird with a very large, thick bill. The shape of the constellation looks like the bird's...

Taurus the bull Constellation
2004-10-19 04:45:44

Taurus (the bull) Constellation -- Location: Zodiac constellation, visible in both Hemispheres; Coordinates: Right Ascension: 04h; Declination: +15; Source: Bull legends from various ancient civilizations, also Greek mythology, Egyptian, Arab, other The constellations that are included in the Zodiac - the 12 constellations recognized by Babylonian astronomers through which our Sun, moon,...

Cygnus Constellation
2004-10-19 04:45:44

Cygnus Constellation -- Cygnus (the swan) is a northern constellation. It was one of Ptolemy's 48 constellations, and is also one of the 88 modern constellations. Because of the pattern of its main stars, it is sometimes called the Northern Cross (in contrast to the Southern Cross). The bird extends over the summer Milky Way, appearing to fly south. Notable features Cygnus contains...

Centaurus Constellation
2004-10-19 04:45:44

Centaurus Constellation -- Centaurus (the centaur) was one of the 48 constellations listed by Ptolemy, and counts also among the 88 modern constellations. A constellation of the southern hemisphere, mentioned by Eudoxus (4th century B.C.) and Aratus (3rd century B.C.), Ptolemy catalogued thirty-seven stars in it. It contains Proxima Centauri, the red dwarf that is the nearest known star...

Terraforming
2004-10-19 04:45:44

Terraforming -- Terraforming (literally, "Earth-shaping") is the process of modifying a planet, moon or other body to a more habitable atmosphere, temperature or ecology. The term was first used in a science fiction novel, 'Seetee Shock' (1940?) by Jack Williamson, but the actual concept is older than that. An example in fiction is 'First and Last Men' by Olaf Stapledon in which Venus is...

Panspermia
2004-10-19 04:45:44

Panspermia -- Panspermia is a theory (more directly described as a hypothesis, as there is no compelling evidence yet available to support or contradict it) that suggests that the seeds of life are prevalent throughout the universe and life on Earth began by such seeds landing on Earth and propagating. The theory has origins in the ideas of Anaxagoras, a Greek philosopher. An important...

Cosmology
2004-10-19 04:45:44

Cosmology -- area of science that aims at a comprehensive theory of the structure and evolution of the entire physical universe. Modern Cosmological Theories Present models of the universe hold two fundamental premises: the cosmological principle and the dominant role of gravitation. Derived by Hubble, the cosmological principle holds that if a large enough sample of galaxies is...

Cosmogony
2004-10-19 04:45:44

Cosmogony -- Cosmogony is the study of the origins of celestial objects. It is most commonly used to refer to the study of the origin of the solar system. Currently, the most widely accepted theory is that the solar system was formed roughly 5 billion years ago with the collapse of a nebula of gas and dust, likely caused by shock waves generated by a nearby supernova. The solar system...

Tycho Brahe
2004-10-19 04:45:44

Tycho Brahe -- Tycho Brahe (December 14, 1546 - October 24, 1601) was a Danish astronomer. He had Uraniborg built; which become an early "research institute". For purposes of publication, Tycho owned a printing press and paper mill. His best known assistant was Kepler. Tycho realized that progress in the science of astronomy could be achieved, not by occasional haphazard observations, but...

Word of the Day
ecotone
  • A transitional zone between two communities containing the characteristic species of each.
The word 'ecotone' comes 'eco-' plus a Greek root meaning 'tension'.