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: LVII
"Worrying does not take away tomorrow's troubles. It takes away today's
peace."
-Unknown

THE DAILY ASTRONOMER Monday, January 3, 2022
January 2022 Night Sky Calendar   Part I

The happiest of new years to you!
Our home world has completed yet another 584 million year circuit about the
average G2V star tucked away inside the Orion-Cygnus arm of the Milky Way
Galaxy, the second largest member of the local galactic group, a paltry
part of the Virgo Supercluster, one of 10 million such clusters scattered
throughout the cosmos.   Or, in other words, another orbit begins on one
world out of countless quintillions scattered throughout a Universe, the
extent of which we have only begun to fathom.

This month brings us an unseen super moon, Earth at perihelion. the
quadratnic meteor shower, Venus in conjunction,  Mercury at greatest
elongation and then in conjunction and so many lunar fly-bys we can hardly
count them all.    Hence, the multi-part night sky calendar.

So, let's begin!


*SUNDAY, JANUARY 2: THE UNSEEN SUPER MOON*
Let's begin the year by reviewing the ever increasing litany of moon
names.  SUPER MOON:  a full or new moon that occurs at or near perigee, its
point of least distance from Earth.  MICRO MOON: a full moon that occurs at
or near apogee, the point of greatest distance  from Earth.  BLUE MOON: the
second full moon of the month; BLOOD MOON: a full moon that passes through
Earth's inner shadow/     Now, add to that list, the UNSEEN SUPER MOON:  a
new moon that occurs at or near perigee.    We'll be experiencing the
unseen super moon today.  Mind you, there is nothing to observe.  The new
moon isn't visible unless it's moving across the Sun's face.

*HOWEVER...*

*[image: poseidon.jpg]*
We can expect Poseidon's tides!  These tides are unusually high tides
caused both by the super moon and Earth's "close approach" to the Sun.   *
 King Tides *occur at each super moon.  However, even higher tides
known as *Poseidon's
Tides *happen when the super moon occurs when Earth is at or near
perihelion, its closest point to the Sun.   (Earth reaches perihelion on
January 4th.)

*MONDAY, JANUARY 3: QUADRANTID METEOR SHOWER PEAKS*
We're glad you're receiving this article just as this meteor shower peaks.
Although, because the Quadrantid Meteor Shower is active between December
28 - January 12, many of its meteors can still be viewed during the next
week.   Also, we can't in good conscience neglect the year's first major
meteor shower.   If nothing else, it presents us with a perfect opportunity
to discuss the science of meteor showers.

First,* meteors *are not objects.  Instead, they are the lights produced
when *meteoroids,* pieces of cometary or asteroidal flotsam, infiltrate the
atmosphere.  The rapidly descending particle excites the atmospheric atoms
within its vicinity.  Electrons within an excited atom are elevated to
higher energy levels.  The electrons then emit light when they return to
their original energy state.  We perceive these light emissions as
meteors.

While we can see one meteor every 6 - 10 minutes on average, during certain
times of year, we experience meteor showers.  These showers occur when
Earth passes through a stream of particles emitted by either a comet or an
asteroid.      between December 28 - January 12, Earth moves through debris
cast off by 2003 EH1. Though described as an asteroid, 2003 EH1 could well
be an *extinct comet*, defined as a comet that no longer sports tails when
passing close to the Sun.

Having an extinct comet as the parent body of the Quadrantids is quite
appropriate, as the constellation for which the meteor shower is named is
likewise extinct.   *Quadrans Muralis, *created by French astronomer Jerome
LaLande (1732-1807), depicted a wall mounted quadrant similar to the one he
used to develop celestial charts.

[image: Quadrans_muralis_map.png]

Although Johannes Bode (1747-1826) included the pattern in his 1801
Uranometria, the International Astronomical Union did not include Quadrans
Muralis in its list of 88 official constellations.   Consequently, the
constellation is no longer recognized.  The Quadrans Muralis region is
around the constellation now designated as Bootes.     The *radiant*, the
point from which the meteors appear to originate, is seen in the image
below.  Bootes is the sheepherder located just off the Big Dipper's Handle.


[image: 11jan03_430.jpg]

While the peak stream (the densest part through which we pass during the
peak) is thin, we can still see about 15 - 25 meteors an hour from
the Quadrantids over the course the next few nights.     The best time to
watch for the Quadrantids is after midnight, the time when our part of
Earth is turning into the meteoroid stream.

Now that we've started 2022, we'll list this year's major meteor showers.
We'll experience quite a gap between the Quadrantids and the Lyrids and
another between the Eta Aquarids and Perseids.  However, one can observe
sporadic meteors on any night of the year.

   - *Quadrantids *   December 28 - January 12;  Peak  Jan 3
   - *Lyrids  *   April 16 - 30;    Peak  April 21
   - *Eta Aquarids *  April 19 - May 28;  Peak May 5
   - *Perseids *  July 17 - August 26; Peak  August 11
   - *Draconids  *October 6 - 10; Peak  October 8
   - *Orionids    *October 2 - November 7;  October 21
   - *Leonids *  November 6 - 30;  Peak  November 17
   - *Geminids  *December 4 - 17 ; Peak December 14
   - *Ursids   *December 17 - 26;  Peak December 22

*MONDAY, JANUARY 3:  MOON NEAR MERCURY*
Oh, this one will be a bit of a challenge.    Try to find the waxing
crescent moon (3% illuminated) and the first world low along the western
evening horizon tonight.    This coupling, though lovely, isn't considered
a  gold, silver or bronze event owing to their proximity to the Sun.  We
advise you to venture outside very soon after sunset to look for this pair.

*TUESDAY, JANUARY 4:   EARTH AT PERIHELION*
We are now moving away from the Sun.   Today, Earth reaches at perihelion,
its point of least distance from the Sun.      Throughout the year, our
planet travels along an elliptical, not circular orbit. What's the
difference?

   -  A* circle *is a closed curve consisting of points equidistant from
   the center.
   - An* ellipse* is a closed curve inside of which one finds two foci.
    The straight line distance from one focus to any point on the curve and
   then to the other focus is a constant.     If the two foci occupy the same
   point, the ellipse becomes a circle.

If Earth's orbit were circular, the planet's distance from the Sun would be
constant.  However, as it travels along an ellipse, Earth's distance varies
continually throughout the year.     Earth reaches perihelion in early
January and aphelion (the point of greatest distance) in early July.

                   [image:
orbital-and-rotational-characteristics-of-earth_02.jpg]
On January 4th Earth's distance from the Sun was 0.983337 AU, or 147.1
kilometers.   [*AU *= Astronomical unit.  Defined as Earth's average
distance from the Sun, an astronomical unit precisely equals  149,597,870.7
kilometers. (92,955,806 miles) . ]

The distance difference between perihelion and aphelion amounts to
approximately three million miles.   How much does that change affect the
weather?    Astronomers define the "solar constant" as the intensity of
solar radiation striking Earth's atmosphere.  Measured in units of
kiloWatts per square meter, the solar constant's average value is 1377
kW/m^2.   However, as we can see in the graph below, the solar constant
value changes in response to Earth's varying heliocentric distance:

[image: earth_sun.jpg]

Although the solar constant is reduced when the Sun is at aphelion and
increased when it is at perihelion, the change is not enough to affect the
weather.

*TUESDAY, JANUARY 4: MOON NEAR SATURN*
If you gave up trying to find Mercury and the moon yesterday, look in the
western sky tonight to see the waxing crescent moon (7% illuminated) and
Saturn, the most distant planet visible to the unaided eye.       Both
bodies will set in the west by 6:30 p.m.

*WEDNESDAY, JANUARY 5:  MOON NEAR JUPITER (SILVER EVENT!!)*
So, let's assume you missed the moon's close approach to Mercury and
Saturn.  Well, heavens, you shouldn't miss tonight's coupling of the moon
and Jupiter,  Find the waxing crescent moon (14% illumintated) and the
bright planet Jupiter in the western evening sky!     A lovely spectacle
which should delight even the most casual of skywatchers.

*FRIDAY, JANUARY 7:   MERCURY AT GREATEST EASTERN ELONGATION (BRONZE
EVENT!)*
The inferior planets Mercury and Venus can never be in opposition because
Earth can never pass between either of them and the Sun.  Instead, these
inner worlds can only reach a maximum elongation from the Sun in our sky.
  These inferior planets are typically easier to find when at maximum
elongation.  Tonight, Mercury reaches greatest eastern elongation, meaning
that it will be east of the Sun and therefore visible in the western
evening sky.      Mercury sets at 5:49 p.m.  tonight.

*SUNDAY, JANUARY 9:  VENUS AT INFERIOR SOLAR CONJUNCTION*
Don't bother trying to find Venus this month as it appears too close to the
Sun to be visible.    Today, Venus passes between Earth and the Sun and
will subsequently move into the eastern morning sky.    We obviously won't
observe Venus today.  However, one can see Venus during an inferior solar
conjunction when it transits the Sun, or passes directly in front of it.
Unfortunately, the next Venusian transit will not occur until December 11,
2117: a bit more than 95 years from now!

*SUNDAY, JANUARY 9:  FIRST QUARTER MOON*





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