Figure: NAAP Applet: Seasons and the Zodiac Simulator

Caption: The Sun's traversal of the ecliptic and the zodiac constellations illustrated by NAAP Applet: Seasons and the Zodiac Simulator.

Further explication:

1. Just push all the buttons and see what they do to gain insight.

2. The Sun moves eastward around ecliptic once per year.

3. Using the red pointer one can make the Sun move on the ecliptic and traversing the zodiac constellations.

   Left click to rotate the ecliptic, the zodiac constellations, and the celestial axis.

4. Your zodiac sign is the zodiac sign the Sun is in when you are born.

   But the zodiac signs are NOT the zodiac constellations.

   The zodiac signs are 30° segments of the ecliptic that start with the vernal equinox.

   Formally, the zodiac is the set of the 12 zodiac signs.

   Informally, the zodiac is also the set of 12 zodiac constellations.

5. The zodiac signs are, in fact, named for the 12 zodiac constellations with which they, zodiac signs, roughly coincided circa the 1st 1st millennium BCE (see Wikipedia: Zodiac: Early history).

   Due to the axial precession, the zodiac signs have moved about 30° west of where they were circa the 1st 1st millennium BCE.

   For example, the sign of Aries is about 30° west along the ecliptic from the zodiac constellation Aries and the Sun passes through the sign of Aries about 30 days before it passes through the zodiac constellation Aries (see Wikipedia: Zodiac: Table of dates).

6. Of course, it is difficult to see the zodiac constellations the Sun is located in. It can be marginally seen at sunrise and sunset. The zodiac constellations opposite the Sun transits the celestial meridian at about midnight, and so is much easier to observe.

7. The terms in the applet need some explanation. As you feel the need, click on any of the keywords in Celestial sphere keywords below (local link / general link: celestial_sphere_keywords.html):

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