THE SOUTHWORTH PLANETARIUM
70 Falmouth Street Portland, Maine 04103
(207) 780-4249 usm.maine.edu/planet
43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded
January 1970
2021-2022: XL
"Snobbery? But it's only a form of despair."
-Joseph Brodsky
THE DAILY ASTRONOMER
Tuesday, November 9, 2021
November 2021 Night Sky Calendar Part II
Well, since the celestial circle conspired to truncate the DA's month,
we'll begin the calendar on November 10th. I'll schedule all future
unexpected hiatuses for times other than the posting of our night sky
calendars.
*WEDNESDAY, NOVEMBER 10: MOON NEAR SATURN*
While the sight of the moon near Venus or Jupiter delights the eye and
enlivens the spirit, it is actually more helpful to see the moon "close" to
a dimmer planet such as Saturn. Tonight one will see the waning crescent
moon (42% illuminated) gliding just south of the magnificent ringed world.*
Both the moon and planet will set by 9:45 p.m. this evening.
*THURSDAY, NOVEMBER 11: FIRST QUARTER MOON*
*THURSDAY, NOVEMBER 11: MOON NEAR JUPITER! (BRONZE EVENT!)*
Yesterday we saw the crescent moon close to Saturn. Tonight, we'll see the
quarter moon "near" Jupiter. While sighting the moon last night might have
helped you locate Saturn, which is 16 times dimmer than Jupiter, one will
experience little difficulty finding Jupiter even without the moon nearby.
Tonight, seeing Jupiter is a cinch. Just find the moon first and look for
the brilliant light close to it.
*WEDNESDAY, NOVEMBER 17: **THURSDAY, NOVEMBER 18:*
* LEONID METEOR SHOWER PEAKS (GOLD EVENT!!!)*
Why list two dates? Simple: the Leonid meteor shower peaks on the night
of November 17-18th. As the best time to watch a meteor shower is
between midnight and the pre-dawn, the best viewing will occur on November
18th.
The Leonid meteor shower occurs between November 6 - 30th. During this
period, Earth moves through a stream of particles released by Comet
Tempel-Tuttle. When this comet moves through the inner solar system. the
Sun's heat causes the comet's surface ice to sublimate: transition from
solid to vapor without passing through the intervening liquid phase. Dust
released from the dissipating ice remains along the comet's path. When
Earth travels through this stream, many of the meteoroids descend through
the atmosphere. During their descent, the meteoroids excite surrounding
atoms, causing their electrons to ascend to higher energy orbits. When
these electrons return to their original states, they emit the photons we
perceive as the meteors.
[image: 09nov16_430.jpg]
The *Leonid Meteor Shower*. Fragments of the Comet Tempel-Tuttle
infiltrate our atmosphere between November 6 - 30. These descending
meteoroids excite nearby atmospheric atoms by elevating their electrons
to higher energy states. These electrons emit photons when they
revert to their original states. We perceive these photons as the meteors.
Meteor showers are generally named for the constellation from which
the meteors appear to emanate, hence the name "Leonid."
Image: EarthSky.org
The Leonid Meteor shower is notorious for producing meteor storms every 33
years approximately. As its parent comet's swoops through the inner
solar system once every 33 years to replenish the meteoroid swarm along the
comet's path.
*FRIDAY, NOVEMBER 19: PARTIAL (BUT NEARLY TOTAL) LUNAR ECLIPSE (PLATINUM
EVENT!!!!)*
Oh, what deliciously good fun one can experience in the wee hours! Tonight,
or, technically, this morning, we can watch the full moon almost completely
pass into Earth's umbra, or inner shadow. As one can see in the graphic
below, the moon's southern limb remains outside the umbra during this
event, hence the term "partial lunar eclipse." We posted the time-line a
few weeks ago and we are now re-posting it:
*NOTE # 1: *The Southworth Planetarium will NOT be open for this event.
However, we will be open for the May 15/16, 2022 total lunar eclipse,
provided that the weather proves cooperative.
*NOTE # 2: * If you do watch this eclipse, be sure to find the Pleiades
Star Cluster which will appear close to the eclipsed moon!
- *1:02 a.m. Penumbral Eclipse begins. *If you wake up just for this
part, you'll be sorely disappointed. The moon's brightness hardly
diminishes at all when passing through the penumbra, or outer part of
Earth's shadow. Apart from the satisfaction of knowing that you're
witnessing a celestial event, the penumbral part will likely not offer much
scintillation or inspiration.
- *2:18 a.m. Umbral Eclipse begins. *Now the action starts! At
2:18 a.m, the moon makes contact with the umbra, defined as Earth's inner
shadow. We can watch Earth's shadow arc migrating across the moon's face.
Initially, it will appear as a fuzzy shade along the lunar limb. That
shadow will soon become sharp and distinct. One can well understand why
some ancient sky watchers ascribed an eclipse to a large black dragon
devouring the moon.
- *4:02 a.m. Maximum Eclipse *Another tricky aspect to this eclipse.
It is not technically total, meaning that the entire moon isn't immersed in
the umbra. Although this eclipse is partial, it's almost total. Let's
look at a lovely graphic:
[image: Lunar_eclipse_chart_close-2021Nov19 (1).png]
Almost all of the moon will pass into Earth's umbra during the November
19th event. However, a small southern sliver won't. This partial eclipse
will therefore look very much like a total lunar eclipse.
- *5:47 a.m. Umbral Eclipse ends *After the moon reaches the maximum
eclipse it will begin the slow move out of the umbra. At 5;47 a.m. the
moon will only be immersed in the penumbra. As a penumbral eclipse hardly
obscures the moon at all, the visual part of this eclipse is over.
- *6:50 a.m. Moon set *Those observers who actually want to see the
penumbral eclipse will have 1 hour and 3 minutes to do so.
- *7:03 a.m. Penumbral Eclipse ends. *Nothing to see here. Of
course, at this phase, there wasn't much to see, anyway.
Note also the following solar time-line:
- *5:00 a.m. Astronomical twilight begins *The Sun will be 18 degrees
from the horizon at this moment. The first hints of atmospheric light
scattering are visible. However, at 5:00 a.m. the sky will still appear
quite dark. Light along the eastern horizon should first become noticeable
around 5:10 - 5:15 a.m.
- *5:34 a.m. Nautical twilight begins. * Nautical twilight begins
when the Sun is 12 degrees below the horizon. Now the horizon becomes
visible and only the brightest stars and planets remain in view.
Incidentally, no planets will truly be visible at this time. Mars rises at
5:31 a.m., but as it will be only moderately bright and very low on the
horizon, it will be exceedingly difficult to observe.*
- *6:09 a.m. Civil twilight begins. *The sun will be six degrees
below the horizon. Welcome to dawn! Only the moon remains visible and will
look no different from any other moon, except it will be full and very
close to the western horizon
- *6:41 a.m. Sun rise*
*Drat! We are unable to see Saturn's rings with the unaided eye. Like all
the other visible planets, Saturn resembles a star except it doesn't
twinkle, or scintillate. The rings are only resolvable in binoculars or
telescopes.
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