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Taurus, in astronomy

(Encyclopedia)Taurus [Lat.,= the bull], in astronomy, constellation NW of Orion and lying on the ecliptic (the sun's apparent path through the heavens) between Gemini and Aries; it is one of the constellations of t...

Gemini

(Encyclopedia)Gemini jĕmˈənī, –nē [key] [Lat.,=the twins], northern constellation lying on the ecliptic (the sun's apparent path through the heavens) between Taurus and Cancer, N of Canis Minor; it is one of...

midnight sun

(Encyclopedia)midnight sun, phenomenon in which the sun remains visible in the sky continuously for 24 hr or longer, occurring only in the polar regions. The midnight sun is due to the fact that the plane of the ea...

solstice

(Encyclopedia)solstice sŏlˈstĭs [key] [Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway between the equinoxes (separated from them by an angular distance of 90°). ...

Al-Battani

(Encyclopedia)Al-Battani ălˌbətēˈnēəs [key], b. before 858, d. 929, Arab astronomer and mathematician. He is best known in astronomy for his improvements and corrections of the Ptolemaic tradition. His Kitab...

seasons

(Encyclopedia)CE5 The seasons are caused by the tilt of the earth's axis to the plane of its orbit about the sun. The Northern Hemisphere is tilted toward the sun in the summer and receives more direct rays than...

retrograde motion

(Encyclopedia)retrograde motion, in astronomy, real or apparent movement of a planet, dwarf planet, moon, asteroid, or comet from east to west relative to the fixed stars. The most common direction of motion in the...

latitude

(Encyclopedia)latitude, angular distance of any point on the surface of the earth north or south of the equator. The equator is latitude 0°, and the North Pole and South Pole are latitudes 90°N and 90°S, respect...

zodiac

(Encyclopedia)CE5 Signs of the zodiac CEE zodiac zōˈdēăk [key] [Gr. zoion=animal], in astronomy, zone of the sky that includes about 8° on either side of the ecliptic. The apparent paths of the sun, the...

Aristarchus of Samos

(Encyclopedia)Aristarchus of Samos ărˌĭstärˈkəs, sāˈmŏs [key], fl. c.310 b.c.–c.230 b.c., Greek astronomer and mathematician of the Alexandrian school. He is said to have been the first to propose a heli...

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