unstable orbit
21star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
22cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
23atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …
24Lagrangian point — The Lagrangian points (IPA en|ləˈgreɪndʒiən, IPA fr|lagʁɑ̃ʒjɑ̃; also Lagrange point, L point, or libration point), are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be stationary… …
25Geometric invariant theory — In mathematics Geometric invariant theory (or GIT) is a method for constructing quotients by group actions in algebraic geometry, used to construct moduli spaces. It was developed by David Mumford in 1965, using ideas from the paper… …
26Kuiper belt — Known objects in the Kuiper belt, derived from data from the Minor Planet Center. Obje …
27Orbital resonance — For the science fiction novel by John Barnes, see Orbital Resonance (novel). In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their… …
28X-ray astronomy — X rays start at 0.008 nm and extend across the electromagnetic spectrum to 8 nm, over which the Earth s atmosphere is opaque. X ray astronomy is an observational branch of astronomy which deals with the study of X ray observation and detection… …
29Multiple star — Artist s impression of the orbits of HD 188753, a triple star system A multiple star consists of three or more stars which appear from the Earth to be close to one another in the sky. This may result from the stars being physically close and… …
30Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
