Explanation:
Twice a year, at the Spring and Fall
equinox,
the Sun rises due east.
In an emphatic demonstration of this
celestial
alignment, photographer Joe Orman recorded
this inspiring image of the Sun rising exactly along the east-west oriented
Western Canal, in
Tempe,
Arizona,
USA.
But he waited until one day after the northern
Spring equinox, in 2001, to photograph the striking view.
Why was the rising Sun due east one day
after the equinox?
At Tempe's latitude
the Sun rises
at an angle, arcing southward
as it climbs above the horizon.
Because the distant mountains hide the true horizon, the
Sun shifts
slightly southward by the time it clears the
mountain tops.
Waiting 24 hours allowed the Sun
to rise just north of east and arc back to an exactly
eastern alignment for the photo.
Today is another Equinox + 1 day, with the Sun crossing the celestial equator yesterday at about 17:32 Universal Time.
