THE SOUTHWORTH PLANETARIUM




*207-780-4249 <207-780-4249>       www.usm.maine.edu/planet
<http://www.usm.maine.edu/planet> 70 Falmouth Street  Portland, Maine 04103
43.6667° N,                    70.2667° W Founded January 1970*


*              "Life has turned us all into tightrope walkers.    Yesterday
is a fading memory, tomorrow is wholly imaginary. and now never sticks
around for long."*





*THE DAILY ASTRONOMERWednesday, April 6, 2016Zodiacal Light*



*Today's schedule allowed us just enough time to address one of Pandora's
many questions.    If you have submitted one and haven't heard a response,
please accept our sincerest apologies.  We are not ignoring your question.
Instead, we haven't withdrawn in from Pandora's jar, yet.     We assure you
that though Pandora will never be empty, each question it contains will
find an answer.*

*This next Pandora inquiry pertains to a sky phenomenon that is rarely ever
discussed: the mysterious "zodiacal light."*

*"I’ve been reading about zodiacal light being visible this time of year in
the northern hemisphere, toward the Taurus constellation. Have you ever
seen it? Are there too many lights in the Portland area for it to be seen
here?"*
-L.B,   Portland, ME



*Zodiacal light is the diffuse glow that one can rarely observe at night
along the ecliptic, defined as the Sun's annual path through the sky.
Zodiacal light appears because the Sun's light illuminates dust particles
gathered around the ecliptic, producing a "light cloud" that is best seen
just after sunset or just before sunrise around either the spring or
fall.     The reason we see this light best in the spring and fall is
because around these times the angle of the ecliptic relative to the
horizon is steep, so the sunlight originating from below the horizon is
aligned with the dust cloud.  In the summer or winter, the sun's angle not
as steep and the sunlight is not as closely aligned with the dust band. *


*Zodiacal light is often mistaken for the Milky Way and sometimes for the
aurora.*   I believe I have seen it about three times.     It is one of
those sky sights that vanishes in moonlight and with any light pollution at
all.  So, it would be exceedingly difficult to see this light when you have
any light pollution at all.  *

*If you do have a dark sky, you might be able to observe the zodical light
around the constellation Taurus, a zodiacal constellation close to the
setting Sun.        Go to the Daily Astronomer web-site to see images of
Zodiacal Light:  usm.maine.edu/planet/da-7-december-2015
<http://usm.maine.edu/planet/da-7-december-2015> [Note: the light in these
images is slightly brighter than the real zodiacal light as the images were
time exposure photographs.]*



**Although the aurora is a northern event, unless it is one of those
dramatic aurora that pervades the sky.      Zodiacal light is eastern or
western.  Rarely it will extend along the entire visible section of the
ecliptic.  *