The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

December 7th marks the beginning of the series of phenomena associated with the winter solstice. This is the evening of the year’s earliest sunset, which in the Washington, DC area occurs at 4:46 pm EST. From this evening onward Old Sol will set a little bit later on successive nights. The change is very incremental at first, but by the time the solstice occurs on the 22nd sunset will be four minutes later. By the end of the year sunset will occur at 4:58 pm. The trade-off comes with the time of latest sunrise. That won’t occur until January 4th, 2012, when the Sun peeks over the horizon at 7:27 am. The shortest day of the year still falls halfway between these dates on the solstice itself, marking the astronomical beginning to the winter season.

The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

The Night After Christmas Sky Show – NASA Science

On Dec. 26th, the night after Christmas, Venus and the slender crescent Moon will gather for a jaw-dropping conjunction in the western sky.

A Venus-Moon conjunction photographed in Nov. 2011 by Thad V’Soske of Fruita, CO. The "Night After Christmas" conjunction will look about the same. Copyright: T. V’Soske/Cosmotions.com

The action begins shortly before sunset. Around 4:30 pm to 5:00 pm local time, just as the sky is assuming its evening hue, Venus will pop into view, glistening bright in the deepening twilight. No more than 6 degrees to the right lies the crescent Moon, exquisitely slender, grinning like the Cheshire cat with his head cocked at humorous attention. This is a wonderful time to look; there are very few sights in the heavens as splendid as Venus and the Moon gathered close and surrounded by twilight blue.

But don’t go inside yet, because the view is about to improve. As the sky fades to black, a ghostly image of the full Moon materializes within the horns of the lunar crescent. This is caused by Earthshine, a delicate veil of sunlight reflected from our own blue planet onto the dusty-dark lunar terrain. Also known as "the Da Vinci glow," after Leonardo da Vinci who first understood it 500 years ago, Earthshine pushes the beauty of the conjunction over the top.

The Night After Christmas Sky Show – NASA Science

I think I was close to 50 before I heard that the latest sunrise and earliest sunset are NOT on the winter solstice, nor the earliest sunrise and latest sunset on the summer solstice (at least, north of the equator). Blew my mind, especially to think I failed to notice in 50+ cycles. Here’s an explanation to pass a long night.

The Dark Days of Winter — Naval Oceanography Portal

The period between the first week in December and the first week in January could well be called the "dark days" for the mid-northern latitudes. At latitude 40 degrees north, earliest sunset occurs around 8 December each year, and latest sunrise occurs around 5 January. The day with the least amount of daylight is the winter solstice, the first day of winter, around 21 December. Why are not all these dates the same? The answer is not simple. There are two effects which, together, determine the local time of Sun phenomena, such as sunrise, sunset, and transit. One is called the Equation of Time; the other is the Sun’s declination. [keep reading…]

The Dark Days of Winter — Naval Oceanography Portal

But then, it was at least 40 years before I realized the swing between summer and winter solstices is 47 degrees.

The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

Full Moon occurs on the 10th at 9:36 am Eastern Standard Time. December’s Full Moon is variously known as the Cold Moon, Frost Moon, Long Night Moon, or Moon Before Yule. Residents of eastern Asia, Australia, and the western Pacific Ocean will see a total eclipse of the Moon at this time. Residents of Alaska and Hawaii will see the eclipse in its entirety, while folks in the western U.S. will see varying stages of it before local moonset, with Washington state getting the best view from the "lower 48".

The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

Total Eclipse of the Moon – NASA Science

Dec. 2, 2011: Waking up before sunrise can be tough to do, especially on a weekend. On Saturday, Dec. 10th, you might be glad you did. A total eclipse of the Moon will be visible in the early morning skies of western Northern America.

The action begins around 4:45 am Pacific Standard Time when the red shadow of Earth first falls across the lunar disk. By 6:05 am Pacific Time, the Moon will be fully engulfed in red light. This event—the last total lunar eclipse until 2014—is visible from the Pacific side of North America, across the entire Pacific Ocean to Asia and Eastern Europe.

For people in the western United States the eclipse is deepest just before local dawn. Face west to see the red Moon sinking into the horizon as the sun rises behind your back.  It’s a rare way to begin the day. …

"I expect this eclipse to be bright orange, or even copper-colored, with a possible hint of turquoise at the edge," [Atmospheric scientist Richard Keen of the University of Colorado] predicts.

Total Eclipse of the Moon – NASA Science

Follow the link above to see a map of the path and for more info. Use www.sunrisesunset.com to determine moonset and sunrise times in your area. [In Albuquerque: Sunrise: 7:03am, Moonset: 7:06am, Full Moon: 7:38am.]

Of course, it’s also a full moon early Saturday. Should look full-ish Fri, Sat, and Sun night. A-OOooo.

The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

December 7th marks the beginning of the series of phenomena associated with the winter solstice. This is the evening of the year’s earliest sunset, which in the Washington, DC area occurs at 4:46 pm EST. From this evening onward Old Sol will set a little bit later on successive nights. The change is very incremental at first, but by the time the solstice occurs on the 22nd sunset will be four minutes later. By the end of the year sunset will occur at 4:58 pm. The trade-off comes with the time of latest sunrise. That won’t occur until January 4th, 2012, when the Sun peeks over the horizon at 7:27 am. The shortest day of the year still falls halfway between these dates on the solstice itself, marking the astronomical beginning to the winter season.

The Sky This Week, 2011 December 6 – 13 — Naval Oceanography Portal

The Sky This Week, 2011 November 29 – December 6 — Naval Oceanography Portal

Even though the winter solstice is still several weeks away, I have always associated the beginning of winter with December 1st, which is when meteorologists shift over to their winter climate models. Early December is when the year’s earliest sunsets occur here in the Northern Hemisphere, and for the next month we’ll seem to experience the full darkness of long winter nights. …

Pay particular attention to the so-called "terminator", the line dividing the sunlit lunar hemisphere from the dark. It is here that the low angle of sunlight exaggerates the shadows of lunar mountains and craters and gives some impression of what a rugged, inhospitable environment the Moon is. Next week marks the 39th anniversary of the flight of Apollo 17, our last human visit to our only natural satellite.

The Sky This Week, 2011 November 29 – December 6 — Naval Oceanography Portal

The Sky This Week, 2011 October 25 – November 1 — Naval Oceanography Portal

The highlight of the week occurs on October 31st. There’s nothing really special going on in the sky that night, but it is my favorite “cross-quarter” day celebration of the year. Halloween is probably the most widely observed of these mid-season markers here in the U.S., but most of the kids (and adults) who dress up and roam the neighborhoods in search of treats probably have little or no clue to the date’s astronomical origins. To the ancient Celts this was a time celebrated as Samhain, the feast of the departing Sun and the traditional beginning of winter in northern climes. Of all the seasonal markers this was the darkest, and it became associated with the spirits of the dead in many cultures. All Saints Day (November 1st), All Souls Day (November 2nd), and Dia de los Muertos (widely celebrated in Mexico and other Latin-American traditions on the 1st and/or the 2nd) all fall at this time of year.

The Sky This Week, 2011 October 25 – November 1 — Naval Oceanography Portal

Quarter days – Wikipedia, the free encyclopedia

In British and Irish tradition, the quarter days were the four dates in each year on which servants were hired, and rents were due. They fell on four religious festivals roughly three months apart and close to the two solstices and two equinoxes.

Quarter days – Wikipedia, the free encyclopedia

Weekend Meteor Shower – NASA Science

Earth is about to pass through a stream of debris from Halley’s comet, source of the annual Orionid meteor shower. Forecasters expect more than 15 meteors per hour to fly across the sky on Saturday morning, Oct. 22nd, when the shower peaks [a few hours before dawn].

Weekend Meteor Shower – NASA Science

The Sky This Week, 2011 October 18 – 25 – Naval Oceanography Portal

The absence of the Moon and the possibility of crisp, clear fall evenings means that it’s time once again for the autumn edition of the Great World Wide Star Count [between October 14th and 28th]. This annual exercise in “citizen science” is intended to not only introduce people to the joys of learning to find their way around the sky, but to also sensitize us to the encroachment of artificial night lighting and its impacts on our environment. The premise is very simple; go outside on the next clear night, identify the constellation Cygnus (for Northern Hemisphere observers) and count the number of stars you see within the constellation’s boundaries. If you live in an urban site try doing the count from your back yard, then try it again from out in the country.

How to find Cygnus…

The Sky This Week, 2011 October 18 – 25 – Naval Oceanography Portal

Cygnus

Cygnus, the Swan, is also known as the Northern Cross because of its shape. The tail of the swan is marked by the bright star Deneb, Arabic for "tail". Three fainter stars cross the line between Deneb and the head of the swan, Albireo. Cygnus flies southward along the summer Milky Way, and into the Summer Triangle.

Cygnus

Cygnus Constellation on Top Astronomer

The Chinese identify the constellation with Que Qiao, the "magpie bridge" that connects the lovers Niu Lang ("the cowherd") and Zhi Nu ("the weaver girl") once a year. It is said that the Goddess of Heaven found out that the two were married and separated them because Zhi Nu, a fairy, could not be with a mortal. Her husband then took their two children and went up to Heaven to be with his wife, but the Goddess would not allow this. She created a wide river in the sky with her hairpin to keep them separated. The river is the Milky Way between Altair and Vega. The story says that once a year, all the magpies in the world form a bridge so that the two can be together, and the constellation represents the celestial bridge.

Cygnus Constellation on Top Astronomer

The Sky This Week, 2011 October 11 – 18 — Naval Oceanography Portal

If you look to the west shortly after sunset you may notice a persistent bright point of light in the twilight glow. Resembling the landing light of a distant airplane, this is really the glimmer of the planet Venus, which is slowly emerging into the evening sky. I had my first glimpse of the returning planet this past weekend looking over the Rappahannock River from Virginia’s Northern Neck. Venus will linger over the twilight horizon until late November, then she will climb rapidly to grace the evening sky by the end of the year. Where Venus requires a bit of work to find, Jupiter is easy to spot once he rises. The giant planet now crests the horizon before 7:30 pm, and by 9:00 pm he’s easily seen in the east.

The Sky This Week, 2011 October 11 – 18 — Naval Oceanography Portal

The Sky This Week, 2011 October 4 – 11 — Naval Oceanography Portal

The Moon brightens the evening sky this week, waxing from First Quarter to Full Moon on the 11th at 10:06 pm Eastern Daylight Time. October’s Full Moon is most popularly known as the Hunter’s Moon because of its similar geometry to last month’s Harvest Moon. In northern latitudes Luna seems to rise at nearly the same time each night for evenings surrounding the Full phase, shedding a little extra bit of light during twilight activities. In September this helps farmers bringing in their crops; in October it helps hunters as they pursue game across the stubble of the harvested fields.

The Sky This Week, 2011 October 4 – 11 — Naval Oceanography Portal

The Sky This Week, 2011 October 4 – 11 — Naval Oceanography Portal

October 8th is the second annual International Observe the Moon Night (InOMN); visit their website for a variety of activities and suggestions of things to look for on the only other world ever visited by humans.

The Sky This Week, 2011 October 4 – 11 — Naval Oceanography Portal