Planet Reference Libraries

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Planetary Astronomy
2014-01-12 00:00:00

Image Caption: Artistic concept of a planetary system. Credit: Wikipedia/NASA/JPL-Caltech The term Astronomy encompasses a broad range of topics, including the study of stars, galaxies, and planets. In order to focus on the different areas of study, many subfields of astronomy emerge. One such area is the study of planets known, appropriately, as Planetary Astronomy. Observational...

Planetary and Space Science
2012-05-28 10:21:45

Planetary and Space Science is a peer-reviewed scientific journal established in 1959 and published by Elsevier 15 times per year. As of May 2012, the editor-in-chief is Rita Schulz (The Netherlands). The journal publishes original research articles and short communications. The main focus is on solar system processes which encompass multiple areas of the natural sciences. Research that...

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...

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...

Terrestrial Planet Finder
2004-10-19 04:45:43

Terrestrial Planet Finder -- The Terrestrial Planet Finder is a proposed NASA telescope system capable of detecting extrasolar terrestrial planets. In May 2002, NASA chose two TPF mission architecture concepts for further study and technology development. Each would use a different means to achieve the same goal - to block the light from a parent star in order to see its much smaller,...

Positional Astronomy
2004-10-19 04:45:43

Positional Astronomy -- Positional astronomy is the study of the positions of celestial objects. This is the oldest branch of astronomy and dates back to antiquity. Observations of celestial objects are important for religious and astrological purposes, as well as for timekeeping. Ancient structures associated with positional astronomy include: -- Chichn Itz -- The Medicine Wheel...

Terrestrial Planet
2004-10-19 04:45:42

Terrestrial Planet -- A terrestrial planet is a planet that is mostly composed of silicate rocks and may or may not have a relatively thin atmosphere. The term is derived from the Greek word for Earth, so an alternate definition would be those planets that are more Earth-like than not. Terrestrial planets are very different from gas giants, which may or may not have solid surfaces and...

Solar Nebula
2004-10-19 04:45:42

Solar Nebula -- In astronomy, the solar nebula is the gaseous cloud from which, in the so-called nebular hypothesis of the origin of the solar system, the Sun and planets formed by condensation. In 1755 the German philosopher Immanuel Kant suggested that a nebula in slow rotation, gradually pulled together by its own gravitational force and flattened into a spinning disk, gave birth to the...

2004-10-19 04:45:42

Planet -- A planet is a body of considerable mass that orbits a star and that doesn't produce energy through nuclear fusion. Until recently, only nine were known (all of them in our own Solar system). As of the end of 2002 over 100 are known, with all of the new discoveries being extrasolar planets. Astronomers often call asteroids minor planets, and call the larger planetary bodies...

Gas Giant
2004-10-19 04:45:41

Gas Giant -- A gas giant is a generic astronomical term invented by the science fiction writer James Blish to describe any large planet that is not composed mostly of rock or other solid matter. Gas giants may still have a solid core - in fact, it is expected that such a core is probably required for a gas giant to form - but the majority of its mass is in the form of gas (or gas compressed...

Word of the Day
  • In dressmaking, straps running from the belt in front over the shoulders to the belt in the back, with more or less elaboration of trimming and outline. They usually broaden at the shoulder and narrow toward the waist.
The word 'bretelles' comes from a French word meaning 'braces'.