http://etcweb.Princeton.EDU/dante/pdp//siteimgs/p3.gif



Mosaic pavement of a 6th century synagogue at Beit Alpha, Israel. Signs of the zodiac surround the central chariot of the Sun (a Greek motif), while the corners depict the 4 "turning points" ("tekufot") of the year, solstices and equinoxes, each named for the month in which it occurs--tekufah of Tishrey, (tekufah of Tevet), tekufah of Ni(san), tekufah of Tamuz.



While in reality the Earth goes in an orbit around the Sun, it seems from the Earth that the Sun moves over the ecliptic (red) on the celestial dome. When the Sun seems to pass through the vernal equinox (longitude 0°), the longitude of the Earth itself is 180° longitude.



The Earth at the start of the 4 (astronomical) seasons as seen from the north and ignoring the atmosphere (no clouds, no twilight).


Source:
Author: Tau ªolunga (http://en.wikipedia.org/wiki/Image:Ecliptic_path.jpg)
http://www-spof.gsfc.nasa.gov/stargaze/Sjewcale.htm