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ether, in physics and astronomy

(Encyclopedia)ether or aether, in physics and astronomy, a hypothetical medium for transmitting light and heat (radiation), filling all unoccupied space; it is also called luminiferous ether. In Newtonian physics a...

dwarf planet

(Encyclopedia)dwarf planet, a nonluminous body of rock or gas that orbits the sun and has a rounded shape due to its gravity. Unlike a planet, a dwarf planet is not capable of clearing its orbit of smaller objects ...

infrared astronomy

(Encyclopedia)infrared astronomy, study of celestial objects by means of the infrared radiation they emit, in the wavelength range from about 1 micrometer to about 1 millimeter. All objects, from trees and building...

neutrino astronomy

(Encyclopedia)neutrino astronomy, study of stars by means of their emission of neutrinos, fundamental particles that result from nuclear reactions and are emitted by stars along with light. Approximately 100 billio...

ultraviolet astronomy

(Encyclopedia)ultraviolet astronomy, study of celestial objects by means of the ultraviolet radiation they emit, in the wavelength range from about 90 to about 350 nanometers. Ultraviolet (UV) line spectrum measure...

radar astronomy

(Encyclopedia)radar astronomy, application of radar to the determination of distances and planetary features within the solar system, such as rotation rates. A short burst of radio waves is transmitted in the direc...

radio astronomy

(Encyclopedia)radio astronomy, study of celestial bodies by means of the electromagnetic radio frequency waves they emit and absorb naturally. Radio waves also come from outside the Milky Way. These extragalact...

Saturn, in Roman religion and mythology

(Encyclopedia)Saturn, in Roman religion and mythology, god of harvests, later identified with the Greek Kronos. Little is known of the origins of his cult. His reign was regarded as the Golden Age. He was the husba...

Piazzi, Giuseppe

(Encyclopedia)Piazzi, Giuseppe jo͞ozĕpˈpā pyätˈtsē [key], 1746–1826, Italian astronomer, a Theatine priest from 1769. He became (1781) professor of mathematics at the Univ. of Palermo, supervised construct...

Demeter

(Encyclopedia)Demeter dĭmēˈtər [key], in Greek religion and mythology, goddess of harvest and fertility; daughter of Kronos and Rhea. She was the mother of Persephone by Zeus. When Pluto abducted Persephone, De...