ZODIACAL LIGHT. A faint luminosity extending outward from both sides of the sun along the ecliptic. It is visible only after sunset or before sunrise. It is easily seen to reach 90° or from the sun; and in favorable circum stances of observation in the tropics, it has been recorded as encircling the sky completely. Where this latter observation has been made, a particu larly bright spot has been noticed in the zodiacal light, located directly opposite the sun's position below the horizon. This bright spot is called by the German name °ego:schen), or 'opposing light.' from its being opposite the sun.
No thoroughly satisfactory explanation has yet been found for this rather puzzling phe nomenon. Some think it merely a very extended outer envelope of the SOM. inelosing the corona (see SuN) and extending very far beyond it into space. A more plausible theory supposes the whole thing to be caused by a ring of small particles revolving about the sun nearly in the ecliptic plane. Such a ring would have an ana logue in Saturn's ring. and in the zone of plane toid:4 (q.v.). And solar light reflected from the countless particles of the ring would give the faint luminosity both of the zodiacal light and the °ego:schen). But the whole theory of this
phenomenon is still in debatable ground. and invites further attention from astronomers.
ZO'E (Lat.. from Gk. Zuoi) (e.97 -l0501 • A Byzantine empress. the last of the Macedonian dynasty. She was the daughter of Constantine by whom she was married to the patrician Pornanns Argyrus. The latter came to the throne in 102S. but was assassinated by z r. and her favorite chamberlain, Michael the Paphlagonian (1034). The Empress thereupon married her accomplice, who reigned as Michael IV. until 1041. After his death the Emnress elevated to the throne his nephew, Michael V., but was imprisoned by the latter. Released with her sister in 1042, Zoe deposed and blinded the young ..\lichael. She then, after sharing the throne for a few months with her sister Theodora, gave the Imperial power to a third husband, Constan tine IX. Alononiachus.