2006-09-12 12:50:45 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
Constellations are determined by the international astronomical union. They first defined the boundaries for the currently recognized 88 constellations in the 1870s. These boundaries are like imaginary lines, and define the entire sky. As the earth precessess in it's orbit, and the stars shift position slightly, they revise the boundaries, usually about once every century or so.
The IAU defines the zodiac as a band of space, approximately eight degrees from either side of the ecliptic. This band crosses through about fifteen constellations as approved by the IAU... and that's how the Zodiac is officially, astronomically definied.
The Zodiac was first defined by Aristotle, and is a band in the sky. Aristotle mentioned twelve collections of star patterns which the zodiac crossed through, and for convenience, he divided these equally. Over the years, precession has made it so that the constellations and the "sign" of the zodiac no longer match... and that's how the zodiac is superstitiously, astrologically defined. People write horoscopes based on which sign the sun is located in at a particular time, and where it was when you were born... and now I must stop before I write up a rant against astronomy.
2006-09-12 13:11:21 · answer #1 · answered by ye_river_xiv 6 · 1⤊ 0⤋
The zodiac is the 12 constellations along the ecliptic. The ecliptic is the apparent path of the Sun in the sky.
2006-09-12 13:55:08 · answer #2 · answered by campbelp2002 7 · 0⤊ 0⤋
Just to correct the person above, the Sun goes through 13 constellations, not 12. Ophiuchus is the "extra" constellation.
2006-09-12 14:40:15 · answer #3 · answered by kris 6 · 1⤊ 0⤋
Hi. They all lie on the ecliptic. And one is Libra, the scales, not an animal.
2006-09-12 12:53:25 · answer #4 · answered by Cirric 7 · 0⤊ 1⤋