neutral particle density
51Cluster (spacecraft) — Cluster Operator European Space Agency in international collaboration with NASA Major contractors Dornier GmbH (now part of EADS) Mission type Orbiter Satellite of Earth …
52Antimatter — For other uses, see Antimatter (disambiguation). Antimatter …
53nuclear fusion — fusion (def. 4). [1895 1900] * * * Process by which nuclear reactions between light elements form heavier ones, releasing huge amounts of energy. In 1939 Hans Bethe suggested that the energy output of the sun and other stars is a result of fusion …
54Magnetosphere of Saturn — Aurorae on the south pole of Saturn as viewed by Hubble Internal field[1 …
55Electric charge — SI symbol: Q SI quantity dimension: Q SI unit: coulomb other units: e Derivations from other quantities: Q = I · …
56Nuclear fusion — Nuclear physics Radioactive decay Nuclear fission Nuclear fusion Classical dec …
57electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
58sun — sunlike, adj. /sun/, n., v., sunned, sunning. n. 1. (often cap.) the star that is the central body of the solar system, around which the planets revolve and from which they receive light and heat: its mean distance from the earth is about 93… …
59Helium — otherusesHelium (He) is a colorless, odorless, tasteless, non toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the… …
60chemical bonding — ▪ chemistry Introduction any of the interactions that account for the association of atoms into molecules, ions, crystals, and other stable species that make up the familiar substances of the everyday world. When atoms approach one another …
