THE SOUTHWORTH PLANETARIUM

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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...

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.       

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.

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.      

                   

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:

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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