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observatory, orbiting

(Encyclopedia)observatory, orbiting, research satellite designed to study solar radiation, electromagnetic radiation from distant stars, the earth's atmosphere, or the like. Because the atmosphere and other aspects...

planetesimal theory

(Encyclopedia)planetesimal theory plănˌĭtĕsˈəməl [key]: see solar system. ...

photovoltaic cell

(Encyclopedia)photovoltaic cell: see photoelectric cell; solar cell. ...

exoplanet

(Encyclopedia)exoplanet or extrasolar planet, a planet located outside the solar system. See planet; planetary system. ...

sunspots

(Encyclopedia)sunspots, dark, usually irregularly shaped spots on the sun's surface that are actually solar magnetic storms. The spots are darker because the temperature of the spots is lower than that of the surro...

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...

synodic period

(Encyclopedia)synodic period sĭnŏdˈĭk [key], in astronomy, length of time during which a body in the solar system makes one orbit of the sun relative to the earth, i.e., returns to the same elongation. Because ...

astronomical unit

(Encyclopedia)astronomical unit (AU), mean distance between the earth and sun; one AU is c.92,960,000 mi (149,604,970 km). The astronomical unit is the principal unit of measurement within the solar system, e.g., M...

Ganymede, in astronomy

(Encyclopedia)Ganymede gănˈēmēdˌ [key], in astronomy, one of the moons, or natural satellites, of Jupiter; the largest natural satellite in the solar system, it is larger than the planet Mercury. ...

Hawthorne

(Encyclopedia)Hawthorne. 1 City (2020 pop. 88,083), Los Angeles co., S Calif., a suburb of Los Angeles; inc. 1922. Located in an oil- and gas-producing area, ...
 

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