THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
Julian date: 2457701.16
"Help! I aspired to be the first sentence in the
Declaration of Independence, but look where I am instead!"
*THE DAILY ASTRONOMERMonday, November 7, 2016 Week 10 Night Sky Calendar*
Consider this week to be the lull before the storm. Next week, we'll have
that uber-super moon which is already generating 100 point headlines.
(Well, almost.) Next week, we'll also experience the peak of the famous
Leonid Meteor Shower. Some would describe it as "infamous" considering
that the Leonids produced a panic-inducing meteor storm in 1833. In
contrast to that celestial extravaganza, this week begins quietly with the
moon at first quarter. Mercury also reaches aphelion. Rather a thin reed
on which to support any self-respecting DA. However, despite the slim
pickings, we'll proceed undaunted. (i.e., we'll stuff it with flannel in
our typical verbose, undisciplined manner.)
MONDAY, NOVEMBER 7: FIRST QUARTER MOON
The technical term is "first quadrature." The moon forms a right angle
with the Sun-Moon line. We consider the first quarter moon to be 50%
illuminated because we see half of its illuminated region. Of course, the
moon, being a sphere exposed to a single and distant light source, is
always half illuminated. The phases result from its changing position
relative to Earth.
*The First Quarter Moon **Known as "first quadrature," the first quarter
moon is said to be 50% illuminated because we see half of its illuminated
region. Of course, the moon is always 50% illuminated as it is a sphere
exposed to a single light source. Interesting note: The first quarter
moon is slightly brighter than the last quarter moon, because the side of
the moon illuminated at the last quarter phase contains more dark regions
that the side we see at first quarter.*
TUESDAY, NOVEMBER 8: ELECTION DAY!!
Not exactly a celestial event, but for those who've been vacationing in the
Andromeda Galaxy until this interminable campaign crashes to an end You
can come home now.
FRIDAY, NOVEMBER 11: MERCURY AT APHELION
Every planet travels along an ellipse, which one can envision as an
oval. The point of least distance is "perihelion." The point of
greatest distance is "aphelion." The distance difference between
perihelion and aphelion depends on the ellipse's elongation. Earth's
ellipse is less elongated than Mercury's, so our planet's perihelion, 91.5
million miles, is only about three million miles less than its aphelion
distance of 94.5 million miles. Mercury's orbit, which is more elongated
than that of any other planet -save Pluto- brings the planet to within 28.5
million miles of the Sun. Its aphelion distance, however, is 43.3 million
miles! Although Mercury is not currently visible, it will be at a
far point in its orbit today.
*Mercury's orbit.** All planets travel along elliptical orbits. These
orbits contain a point of greatest distance (aphelion) and a point of least
distance (perihelion.) Mercury completes one orbit in approximately 88
days and therefore reaches aphelion and perihelion about four times a
year. *
*PLANET WATCH*
*MERCURY (Host constellation: Libra)*
Mercury is not visible until late November, when it will emerge in the
western evening sky. Mercury passed into superior solar conjunction on
October 27th. For three weeks following this conjunction, Mercury will be
too close to the Sun to be visible. VERDICT: Don’t bother to search
for Mercury until around Thanksgiving week, when it will high enough in the
west for viewing. It will return just before Thanksgiving week, but will
be exceedingly difficult to observe.
*VENUS: (Host constellation: Ophiuchus) PICK PLANET!*
As far as brightness is concerned Venus enjoys all the advantages. Its
pervasive clouds reflect about 67% of the sunlight it receives. It is
closer to the Sun than Earth, so the incidental sunlight is more intense.
It is also one of the closest planets to Earth, so the reflected light
isn't as diminished as it would be were it farther away. Also, Venus is
almost as large as Earth, so its reflective surface area is larger than the
other two terrestrial planets, Mars and Mercury. Venus is often the
pick planet because of these advantages. Venus remains a bright beacon
in the western evening sky throughout November. VERDICT: Easy to see
if one ventures outside soon after sunset. Venus is one of those celestial
bodies that appears during civil twilight. Seek it out in the early
evening western sky.
*MARS (Host constellation: Sagittarius)*
Careful observers will notice something rather peculiar about Mars. It
sets around the same time (9:30 p.m.) each night through November, just as
it did for most of October. This occurs because Earth and Mars are moving
relative to each other in such a way so that Mars' position relative to the
Earth-Sun line remains the same…at least for now. VERDICT: Even
though it is nearly 100 times dimmer than Venus, Mars is still a
conspicuous sight in the western evening sky. It will also remain visible
for about two hours after Venus sets.
*JUPITER (Host constellation: Virgo)*The second brightest planet, Jupiter
outshines all the night sky stars, but rises in the early morning eastern
sky. In fact, Jupiter is currently the only visible planet in the
morning sky. Jupiter rises a few minutes earlier each day and slowly
brightens throughout the year. VERDICT: If you're up before dawn,
treat yourself to some delectable eye candy. If you'd rather remain in
beautiful communion with your bed, you can wait to see Jupiter at more
decent hours later this winter.
*SATURN (Host constellation: Ophiuchus)*We lose Saturn just after mid
month. One might observe the sixth world low in the southwestern evening
sky during the first three weeks of November. Otherwise, it will be
lost to sight. Saturn passes through superior solar conjunction on December
10th and then will return to the pre-dawn eastern sky by late December.
VERDICT: Try to find Saturn before November 23rd. After that, wait until
the end of the year.