THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Altitude: 10 feet below sea level
Founded January 1970
Julian date: 2458729.5
2019-2020: I
“Exercise your genius so often that you live in a perpetual state
of runners high.”
-Curtis Tyrone Jones
(and, yes, we are talking
to YOU!)
THE DAILY ASTRONOMER
Tuesday, September 3, 2019
September 2019 Night Sky Calendar
*__________________________________________*
*School year dedicated to my soon-to-be wife,*
*Susan, whom I love beyond all measure and will*
*adore until the end of time, which some quantum theorists insist*
*has already happened, but who believes anything*
*those chuckleheads say.*
*___________________________________________*
Let's start!
*Silly Sam, seeking Sarah, mistakenly sent secret messages to her twin
sister, Serena, who then secretly loved Sam, who still sought Sarah, who,
knowing Sam sent messages to her Sam-coveting sister Serena, thought him
too silly and suddenly sought another suitor. *
What a stupid way to being a new DA school year!
However, please indulge us for a moment and re-read that sentence and then
return: did you notice what had happened during the moments when you were
reading that preposterous sentence?
More than 140,000 stars were born through the Universe; your brain
manufactured new neural pathways; Earth moved more than 3,700 miles around
the Sun; stars from the Sagittarius Dwarf Galaxy continued to be
inexorably drawn closer to the Milky Way Galaxy; dozens of airplanes
launched; thousands of your cells perished as others took form; the Sun
burned 3 billion tons of hydrogen in its core; many metric tons of heated
air ascended from the jungle floor; Earth's plates nudged each other
slightly; fragments of rock eroded from wind-swept Himalayan summits; the
Voyager 1 craft ventured more than 1000 miles farther through unchartered
space; Stonehenge's sentinel stones aged a few more moments; five children
were born; you inhaled oxygen atoms that have passed through the lungs of
billions of humans; somewhere a wolf pack pressed their footfalls into some
hyperborean snow; charged solar particles became entangled in the Van Allen
Belts; some light from Alpha Centauri's stars drew 2 million miles closer
to the Sun; two people drew their last breaths; the Andromeda Galaxy inched
15,000 miles closer to the Milky Way; tons of acorns plummeted to forest
floors around the continent; 800 lightning bolts struck Earth; all the
humans who are now running collectively covered thousands of miles; the
cars currently in operation more than a million; the Sun set on a million
souls and rose on a million others; your hair grew; Earth's super hot
iron-nickel core turned, ever so slightly faster than Earth, itself;
Thousands, or perhaps even millions of life-bearing worlds spun and
revolved around stars in our galaxy; the cosmos expanded....
Life continues to thrive on a spinning world in a ceaselessly evolving
Universe we are only just beginning to fathom. We don't need to add that
every single second of living in this miraculous cosmos is like gold that
required 13 billion years of alchemy to produce. The Universe
communicates this notion to us constantly. We just happened to evolve the
strange ability to render ourselves deaf to it.
This year, the DA will try to deliver small morsels of the cosmos every
weekday, apart from those times when we decide that we deserve a vacation.
Please send us your questions, concerns and ideas! We promise to read them
all and, time permitting, answer them all, as well. Also, having been
fashioned by human DNA, We are annoyingly fallible and will often prove
that lamentable fact repeatedly. If we err, please feel free to let us
know. Also, the DA is only one person, so the "we" is utterly
inappropriate. We use "we" because there is no "I" in "team." Of course,
there is no "we" in "team," either.
We are immensely excited about the coming school year because we have so
many places to explore. We'll hop from the nether edge of our electric
atmosphere to the farthest shores of the distant Universe. Every single
point in the space-time matrix from the first moments after the Big Bang to
the last moments in time, if such moments even exist.
Thank you for agreeing to accompany us for however long you wish to remain.
Now, to begin the September 2019 Night Sky Calendar.
*WEDNESDAY, SEPTEMBER 4: MERCURY AT SUPERIOR CONJUNCTION*
Heavens above, Mercury moves! Well, granted, all the planets move.
However, Mercury, being the closest planet to the Sun, moves madly around
its parent star at speeds often exceeding 160,000 miles an hour! At that
steady clip, the first world completes an orbit around the Sun about once
every 88 days. Mercury doesn't remain in one position for long. Today,
Mercury moves to the far side of the Sun relative to Earth. It can't be
seen today. However, later this month, Mercury will ascend into the
western evening sky and then will gradually maneuver back toward the Sun
prior to its November 11th transit!
*FRIDAY, SEPTEMBER 6: FIRST QUARTER MOON*
Mercury indeed moves quickly, but it has nothing on the moon, at least from
our perspective. While Mercury might be moving many thousands of miles per
hour faster than the moon, the latter appears to race across our sky with
greater speed. The moon shifts position by half a degree an hour, or
about twelve degrees a day. As it revolves around Earth, the moon's
location relative to the Sun and, consequently, its phase, changes.
Today, the moon will be at the first quarter position. It will rise at
2:29 p.m. and set at 11:52 p.m.
*FRIDAY, SEPTEMBER 6: MOON NEAR JUPITER * (BRONZE EVENT!)
See the first quarter moon near Jupiter tonight! Distinguishing between
these two worlds won't prove difficult, as Jupiter will resemble a star,
albeit a particularly bright one that doesn't "twinkle." (Planets don't
show any scintillation unless they're close to the horizon.)
*SUNDAY, SEPTEMBER 8: MOON NEAR SATURN!*
How many times have you looked out the window on a brisk February morning
and lamented, "Oh, if only I was in Papua New Guinea!" If you were, you
would see the moon "occult" Saturn! From this perspective, the moon would
appear to move directly in front of the ringed world. However, we here
in the northern climes will merely watch the moon appear to draw close to
Saturn, still a beguiling spectacle.
*TUESDAY, SEPTEMBER 10: NEPTUNE AT OPPOSITION.*
Wait! We can't see Neptune, can we?
Well, not without a telescope. However, Neptune is still a planet in the
solar system and, provided you had a sufficiently powerful telescope, you
could see Neptune tonight rising around sunset and setting around sunrise.
As it is at opposition, Neptune is closest to Earth now (about 2.69
billion miles) and at its maximum brightness (2.2 times dimmer than the
faintest star visible to the unaided eye). All the same, this is the best
time in 2019 to seek out Neptune!
*SATURDAY, SEPTEMBER 14: FULL MOON - HARVEST MOON (SILVER EVENT!!)*
[image: moonrise-red-oregon.jpg]
Comforting, isn't it? The consistent seasonal changes that occur
throughout the year merely as a consequence of living on a tilted sphere in
orbit around an active star. No matter what other changes affect us, we
can always rely on the seasonal progressions. Today, we experience the
latest "Harvest Moon," defined as the full moon that occurs closest to the
autumnal equinox. By this definition, there have been billions of such
harvest moons. The name itself is of more recent coinage; in print, we
can trace the name to early 20th century Farmer's Almanacs. The list of
full moon names derives from Native American tradition long predating the
Almanacs' publications.
As the Harvest Moon occurs around the equinox, it will rise soon after
sunset and remain visible throughout the night. The full moon that occurs
around the winter solstice follows a longer arc across the sky and remains
in the sky for longer than twelve hours. The full moon that occurs around
the summer solstice moves along a shorter arc and is above the horizon for
less than twelve hours. The Harvest Moon is so named because it provides
much needed illumination to farmers who often had to harvest their crops
through the name. Even though modern lighting has rendered such moon
light unnecessary for harvesting, the term "Harvest Moon" remains with us.
___________________________________________________________________________
*THE MOON-STAR SCHEDULE*
Four truly bright stars are located so close to the ecliptic, the Sun's
path through the sky, that the Moon will draw close to them and, during
certain times, actually occult them. These stars are Aldebaran (Taurus the
Bull), Antares (Scorpius), Regulus (Leo the Lion), and Spica (Virgo the
Maiden). Each month, we'll list the approach schedule between the moon and
these stars in a separate section. If the moon happens to occult any of
these stars from our perspective, we'll devote a separate paragraph to that
event.
You will find the moon close to the stars on the following dates:
SPICA: September 2
ANTARES: September 5
ALDEBARAN: September 20
REGULUS: September 26
_____________________________________________________________________________
*SUNDAY, SEPTEMBER 22: LAST QUARTER MOON*
*MONDAY, SEPTEMBER 23: AUTUMNAL EQUINOX (GOLD EVENT!!!)*
At *3:50 a.m.* today, astronomical autumn will begin! (That means that
when you receive this calendar on Sept 3rd, you'll have almost three weeks
of astronomical summer left to enjoy!) The reason for the seasons is
quite simple: Earth is tilted on its axis by 23.5 degrees. As Earth
revolves around the Sun, the Sun's angle changes from a maximum on the
summer solstice to a minimum on the winter solstice. On the autumnal and
vernal equinoxes, the Sun's angle is midway between these two extremes.
[image: fig7seas.png]
*-The Sun rises due east and sets due west on the autumnal equinox*
*-The Sun passes directly overhead along the equator*
[image: aeb0201c4edc3d3dd65175b463412b18.png]
The Sun's daily path through the sky changes throughout the year. On
the summer solstice, the Sun's path is long and high. On the winter
solstice, it's
shorter and quite low. On the autumnal and vernal equinoxes, the Sun rises
due
east and sets due west. The Sun's path will continue to descend through
the next three months until we reach the winter solstice on December 21st
at 11:19 p.m.
*SATURDAY, SEPTEMBER 28: NEW PERIGEAN MOON*
Watch the tides! They'll be higher than usual because the moon is new (in
conjunction) and at perigee, its point of least distance from Earth, on the
same exact day: September 28th. The moon is not always closest to Earth
when new or full because the period of time separating successive full
moons, called the synodic period, is 29.5 days, whereas the period of time
separating successive perigees, an anomalistic month, is 27.55 days. We
won't actually see the moon when its new, but we might well notice the
profound effect the moon is having on the ocean because the tides are
affected by the Moon, Sun and by Earth's distance from both.
When the moon is new or full around the time of perigee, we'll experience *King
Tides.*
When the moon is new or full around the time of perigee and around the time
of perihelion (Jan 3 - 4),
when Earth is closest to the Sun, we'll experience *Poseidon's Tides. *
*SUNDAY, SEPTEMBER 29: MOON NEAR VENUS*
The thin sliver moon (2% illuminated) will appear close to Venus in the
western evening sky. Now that Venus is returning to the evening sky (see
PLANET WATCH), see it coupled with the moon low in the evening sky. Both
planet and moon will set about an hour after Sunset.
*PLANET WATCH*
*MERCURY *will not be visible until mid month, when it will appear in the
western evening sky. Mercury passes around the far side of the Sun on
September 4th and will emerge in the evening sky about two weeks later.
Verdict: If you're outside later this month seeking out Venus, look
for Mercury, as well. It won't be nearly as bright, of course, but won't be
exceedingly difficult to find, especially around late September.
*VENUS *will also not be visible during the first half of September.
However, Venus will appear in the western evening sky by mid month and will
remain a brilliant evening sky beacon for the rest of 2019. Verdict:
Honestly, start looking for Venus around the time of the autumnal equinox.
It is always worth your time.
*MARS* is not visible this month. Spoiler: it will reappear in October
and over the subsequent twelve months will rise progressively earlier and
grow brighter as it approaches its opposition in mid October 2020.
*[PICK PLANET] JUPITER* is the brighter of the two evening sky planets
this month. (The other is Saturn) Jupiter remains in the western evening
sky and will set after midnight early in September and before midnight in
late September.
*SATURN *trails behind Jupiter and, though it is six timers dimmer than
Juputer is still about as bright as Procyon, the brightest star in Canis
Minor. Saturn will remain in our evening sky each night until late 2019.
Verdict: If you're seeking out Jupiter, look to the east to spy
out Saturn!
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