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
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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.
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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!!)
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.
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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.
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
ALDEBARAN: September 20
REGULUS: September 26
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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.
-The Sun rises due east and sets due west on the autumnal equinox
-The Sun passes directly overhead along the equator
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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