[TowerTalk] Equinox Day

[Michael Keane, K1MK]

At 02:03 PM 3/15/03, Jim Reid wrote:

>Why today, and not on/nearer the 21st? Two reasons actually,
>our latitude is only 21.9N and the Earth's orbit about
>the Sun is elliptical,  not circular.  Actually,  the center of the
>Sun is still 2 degrees South of the Equator today.

No. It's due to the non-zero angular diameter of the sun plus atmospheric 
refraction...

See: <http://aa.usno.navy.mil/faq/docs/equinoxes.html>


Michael Keane K1MK
k1mk at alum.mit.edu