September
Armillary Sphere
23
|
The first day of fall is the Autumnal Equinox. The heavenly bodies that move along the ecliptic continue reach the midpoint of their path from north to south and will continue to sink lower into the sky throughout the fall. If you started on the March 21st page of this exhibit, you already know where the sun will rise and set on September 22. If not, take a guess, watch the demonstration, and visit the March 21st page! |
Watch the demonstation
The sun rises exactly in the east (90 degrees by the compass) and sets exactly in the west (270 degrees by the compass).
Look carefully at the model and you can see that September 22nd is one two times where the ecliptic (the imaginary elliptical path followed by the sun, moon, planets, and zodiac constellations) and the celestial equator (the imaginary circle in the sky above and following the earth's equator) cross paths.
Choose another date
How to read an armillary sphere
Watch the sun's path (the ecliptic) move through the year
Back to Armillary Sphere Page
Back to Universe in Your Hands (for sundials & astrolabes)
All images copyright 1999, The Adler Planetarium and Astronomy
Museum.
This page, including all components (writing, graphics, photography
and videography), was designed and executed by Lisa Schuyler Jewell.
Any inquiries about the Adler site should be directed to webmaster@adlerplanetarium.org