4 results found
perigee(Encyclopedia)perigee pr´j [key], point nearest the earth in the orbit of a body about the earth. See apsis. ...
apsis(Encyclopedia)apsis (pl. apsides), point in the orbit of a body where the body is neither approaching nor receding from another body about which it revolves. Any elliptical orbit has two apsides. At the perigee the...
satellite, artificial(Encyclopedia)satellite, artificial, object constructed by humans and placed in orbit around the earth or other celestial body (see also space probe). The satellite is lifted from the earth's surface by a rocket an...
moon(Encyclopedia)moon, natural satellite of a planet (see satellite, natural) or dwarf planet, in particular, the single natural satellite of the earth. The Earth-Moon System The moon is the earth's nearest neighbor i...
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