Moonrise Over Seattle
Credit & Copyright:
Shay Stephens
Is the Moon larger when near the horizon?
No -- as shown above, the
Moon
appears to be very nearly the same size no matter
its location on the sky.
Oddly, the cause or causes for the common
Moon
Illusion are still being debated.
Two leading explanations both hinge on the
illusion
that foreground objects make a
horizon Moon
seem farther in the distance.
The historically most
popular explanation then holds that the
mind interprets more distant objects as wider, while a
more
recent explanation adds that the distance illusion
may actually make the eye focus differently.
Either way, the
angular
diameter of the Moon is always about 0.5
degrees.
In the above time-lapse sequence taken near the end of 2001,
the Moon was briefly re-imaged every 2.5 minutes,
with the last exposure of longer duration to bring up a
magnificent panorama of the city of
Seattle.