The New Year’s Eve Skies of 2019

   The evening skies of this year’s New Year’s Eve begins at sunset with the 6-day old waxing crescent Moon to be about 3-4o from the outer planet Neptune. However with an apparent magnitude of 8 Neptune is only visible with optical assistance. On the other hand the crescent Moon with an apparent magnitude of -13 would be hard to miss!

   Later, at around midnight and centered over the southern horizon will be the ‘regular’ Northern Hemisphere winter display of stars. This is a familiar groups of bright stars in a rough circle around the constellation of Orion the Hunter, and sometimes referred to as the “Winter Hexagon” or ‘Winter Circle”.

   As the winter hexagon the member stars are Rigel in Orion the Hunter, Aldebaran in Taurus the Bull, Capella in Auriga the Charioteer, Pollux and Castor in the Gemini Twins, Procyon in Canis Minor, and Sirius in Canis Major.


   
   
   
   We’ve survived another orbit.
   
   
          Happy New Year!
   
   
   
   
   
   
   
   
   

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Moon – Venus Conjunction

   Friday evening December 28th over the western horizon around sunset look for the 3-day old waxing crescent Moon to be about 2o from the inner planet Venus. Both will easily fit within the field of view of binoculars.

   I should clarify that the view of the conjunction as described above is based on my latitude and longitude in the midwest U.S.A. The separation between the Moon and Venus will vary depending on your location. At other geographic locations, like southern South America and Antarctica, the crescent Moon occults Venus.

   The occultation begins at 2 UT or for my time zone at 9:00 pm CST.

   This animated graphic is set for a latitude of 56oS to show the Venus Occultation. Venus was also enlarged to make it more visible in the graphic.

   
   
   

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Where is Jupiter?

   For the past several months the outer planets Jupiter and Saturn have been the brightly shining ‘evening stars’ over the western horizon at sunset. They have recently been joined by the inner planet Venus, but at the same time as Venus has become more prominent each evening Jupiter and Saturn have been setting earlier as they gradually move closer to the horizon at sunset.

   And now Jupiter is no longer in the ‘picture’. So what happened to Jupiter, and will soon happen to Saturn? All solar system objects orbiting the Sun beyond Earth’s orbit move at a slower pace around the Sun than the Earth. The Sun has an apparent motion toward the east which is the same as the Earth’s actual motion. So what happens is that over time the Sun catches up with Jupiter, then Saturn. Eventually the Sun passes them and the planets become visible in the morning skies rising ahead of the Sun.

   At some point along their respective orbital path they will be on the opposite of the Sun from the Earth. This is known as solar conjunction, and that is where Jupiter will officially be on Friday December 27th.

   
   
   

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December Moon at Descending Node and an Eclipse

   Thursday December 26th the Moon, at new Moon phase, crosses the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path (dark green line) has with the ecliptic.
   What happens when the Moon is at new phase and is also at a node crossing? You get an eclipse of the Sun, which in this instance will be an Annular Solar Eclipse. This is a solar eclipse however the Moon is far enough from the Earth that it appears to be smaller than the Sun. So, unlike with a Solar Eclipse where at mid-eclipse the Moon’s disk covers the Sun’s disk, during mid-annularity the Moon’s disk does not completely cover the disk of the Sun but instead leaves a ‘ring of fire’ known as the annulus around the Sun.

This eclipse will be visible from Saudi Arabia to south of the Philippine Islands.

Note: The picture I used for the banner is of the 2011 Annular Eclipse and it is from the NASA Hinode satellite. Also at the NASA web page the link takes you to is a video of the Annular Solar Eclipse as seen from the satellite in Earth orbit.


Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Mid-Winter Skies

   Tuesday evening December 24th around sunset or after the skies darken look toward the western horizon and you can’t miss noticing the bright celestial object – the inner planet Venus. Also, despite the fact that we are now two seasons away from our summer (Northern Hemisphere), over the western horizon are three stars making up the ‘Summer Triangle’. These three stars each belong to a seperate constellation but together they form an asterism,not a constellation, but a recognizable star shape.

   Wednesday morning December 25th look toward the eastern horizon for the ‘Red Planet’ (Mars) to be above the horizon and about 15o from the reddish star Antares in Scorpius the Scorpion. In this graphic Antares is just above the horizon.
Higher above Mars, toward the right or the west, is a the bluish star Spica in Virgo the Harvest Maiden. And higher still but toward the left is another reddish star. This is Arcturus in Bootes the Herdsman.

   As this year and decade come to a close I’d like to thank all my readers and the universe in general for allowing me an opportunity to share things celestial.
Have a happy and safe Holiday however you celebrate.


Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Waning Crescent Moon Near Mars

   Monday morning before the Sun rises the 27-day old Moon waning crescent Moon will be about 4-5o from the ‘Red Planet’ Mars. Both will be over the southeastern horizon rising at least 2-3 hours ahead of the Sun.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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December Solstice – 2019

sag-cap-ani    According to the pseudoscience of astrology the Sun enters the constellation of Capricornus the Sea Goat this month when in fact the actual position of the Sun is still within the boundaries of the constellation of Sagittarius the Archer.
    In Astronomic terms the December Solstice is official when the Sun will have reached the celestial coordinates of 23.5o degrees south declination; 18 hours right ascension. With regard to the Earth’s surface this places the Sun over the Tropic of Capricorn, which is at 23.5o south latitude. We also know that it is the Earth’s tilt on its axis that is the cause for seasons on Earth rather than the distance between the Earth and the Sun. And of course we know that this signals the start of northern hemisphere winter and the southern hemisphere summer seasons.

    The official time for the change of seasons is at 4:21 UT on Sunday December 22nd, or 10:21 pm CST Saturday December 21st.
earth-in-gemini

    And for those ‘insanely curious’ like me, while the Sun is at 23.5o South declination and ‘in’ Sagittarius the Earth is opposite at 23.5o North declination and at the feet of the Gemini Twins.

    The animated graphic below sets the stage, so to speak, to illustrate the Sun’s actual location with respect to the zodiac constellations in the background. This is as opposed to the location of the Sun according to the pseudoscience of Astrology. The scene is set for 12:15 CST, or mid-day when the Sun is at an azimuth of 180o, or south, and is mid-way between rising and setting. Starting with the Sun at mid-day the scene changes as first the daytime sky is turned off, followed by the horizon being turned off.
   This leaves a sky view like during a total solar eclipse except that the Sun is not blocked out by the new Moon. And like during that solar eclipse the zodiac constellations in the background become visible. Then the following are added starting first with Sagittarius, then Capricorn, and then the ecliptic and celestial equator are added to show the relationship between the two constellations and what makes them plus another 11 constellations the astronomical zodiac of 13 constellations. The animation ends with the addition of the constellation boundary lines and labels for the rest of the constellations in this setting.
It is the ecliptic, the apparent path of the Sun which, if it crosses the boundary of a constellation, makes that constellation one of the zodiac. And during December the Sun’s apparent path takes it across the constellation of Sagittarius rather than Capricorn.

    Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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Sun Does Enter Sagittarius

16dec-view-from-earth   Wednesday December 18th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Ophiuchus the Healer and into the constellation of Sagittarius the Archer. This is the true or actual position of the Sun as opposed to the pseudoscience of astrology which usually has the astrological Sun one constellation ahead or east from the Astronomical Sun’s position. Ophiuchus the Healer is the 13th Astronomical Zodiac constellation based on the location of the ecliptic and the Sun’s actual position relative to the stars and constellations in the background.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.

   
   
   

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December Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Wednesday December 18th. At that time the Moon will be at a distance of 26.025 Earth diameters, 230,069 miles (370,260 km) from the Earth.

   On the day of the perigee Moon the 22-day old waning gibbous Moon will be over the south-southwestern horizon at sunrise local time. The planet Mars is also visible over the southeastern horizon. If your local eastern horizon is low enough then the innermost planet, Mercury, might be seen near the reddish star Antares in Scorpius the Scorpion.

   Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*
   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

   
   
   

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Moon on the Move

   Over the next few evenings, Saturday December 14th, Sunday the 15th, and Monday the 16th the waning gibbous Moon will orbit eastward starting from about 7-8o south of Pollux to passing about 6-8o from M-44, the ‘Beehive Cluster’, an open star cluster in the constellation Cancer the Crab. By Monday the 16th the waning gibbous Moon will be about 2o from the heart of Leo the Lion, the star Regulus.
   During a 24-hour rotation of the Earth the Moon will have moved approximately 15o eastward. In terms of Moon position that 15o is equal to one hour — (divide 360o by 24 hours = 15o). What this has to do with the Moon’s position is that each day or night the Moon rises about 1 hour earlier. These 3 graphics show the effect of this in that it will be about 1 hour later for the Moon to be more or less in the same spot in the sky relative to the horizon.

   
   
   

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