Space Sciences
Cosmogony
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 bill...
Cosmology
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 princip...
Kepler's Laws of Planetary Motion
Kepler's Laws of Planetary Motion -- The astronomer Johannes Kepler's main contribution to astronomy was his three laws of planetary motion. Kepler found these laws empirically by studying extensive observations recorded by Tycho Brahe. He found th...
Lagrangian Point
Lagrangian Point -- In Lagrangian mechanics, a Lagrangian point (or L-point) is one of five positions in space where the gravitational fields of two bodies of substantial but differing mass combine to form a point at which a third body of negligible ma...
Large-Scale Structure of the Cosmos
Large-Scale Structure of the Cosmos -- Stars are organised into galaxies which in turn appear to form clusters and superclusters, separated by voids. Prior to 1989 it was commonly assumed that the superclusters were the largest structures in existe...
M-Theory
M-Theory -- 'M-Theory' is the name of the unknown theory of everything which would combine all five Superstring theories and the Supergravity at 11 dimensions together. The theory requires mathematical tools which have yet to be invented in order t...
Panspermia
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 be...
Retrograde Motion
Retrograde Motion -- Retrograde motion is the orbital motion of a body in a direction opposite that which is normal to spatial bodies within a given system. 'Retrograde' derives from the Latin words retro, backwards, and gradus, step. In the Solar ...
Search for Extra-Terrestrial Intelligence (SETI)
Search for Extra-Terrestrial Intelligence (SETI) -- SETI (pronounced SEH-tee) stands for for Search for Extra-Terrestrial Intelligence. Interstellar travel is a common theme in science fiction stories, but the obstacles to such journeys are in prac...
Xenobiology (exobiology)
Xenobiology -- Xenobiology (or exobiology, or astrobiology) is the term for a speculative field within biology which considers the possibility of, and possible nature of, extraterrestrial life. It also necessarily includes the concept of artificial...
String Theory
String Theory -- A string theory is a physical model whose fundamental building blocks are extended objects (strings, membranes and higher-dimensional objects) rather than points. String theories are able to avoid problems, such as infinite energy ...
Terraforming
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...