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ring, in astronomy

(Encyclopedia)ring, in astronomy, relatively thin band of rocks and dust and ice particles that orbit around a planet in the planet's equatorial plane. All four of the giant planets in the solar system—Jupiter, S...

nucleus, in biology

(Encyclopedia)nucleus: see cell, in biology.

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

nun, in religion

(Encyclopedia)nun: see monasticism.

nut, in botany

(Encyclopedia)nut, in botany, a dry one-seeded fruit which is indehiscent (i.e., does not split open along a definite seam at maturity). Among the true nuts are the acorn, chestnut, and hazelnut. Commonly the word ...

nymph, in zoology

(Encyclopedia)nymph, in zoology: see insect.

Pan, in astronomy

(Encyclopedia)Pan, in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn XVIII (or S18), Pan is 12.5 mi (20 km) in diameter, orbits Saturn at a mean distance of 83,000 mi (133...

Pandora, in astronomy

(Encyclopedia)Pandora păndôrˈə [key], in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn XVII (or S17), Pandora is an irregularly shaped (nonspherical) body measuring a...