Friday, December 11, 2015
The Ellensburg WA sky for the week of 12/19/15
Saturday: Today: I know you’re staying up late to train yourself to wait up for Santa. So look out a south-facing window at 1 a.m. and see Sirius, the brightest star in the nighttime sky, as high as it ever gets in the sky. It is two and a half fists held upright and at arm’s length above due south.
Sunday: Two of the best, and certainly the most available, “tools” for viewing the night sky are your eyes. Your eyes let you see the entire sky in just a few seconds. Your eyes can read star charts, decipher astronomy apps, and spot meteors while your friend is still setting up her tripod. Your naked eyes are not as effective as gathering light. They work well when the light source is comparatively bright and the detailed features are fairly large. It’s best to practice on a special Solar System body known scientifically as the Magnificent Optical Object of Nearness. Artists such as Jan van Eyck and Leonardo da Vinci produced the first realistic naked eye depictions of the Magnificent Optical Object of Nearness. This week you can use your own eyes to observe evidence of violent collisions and ancient lava flows. For more information to observe the Magnificent Optical Object of Nearness, better known as the Moon, go to http://goo.gl/JLhraO.
Monday: At 8:48 p.m., the Sun reaches its lowest point in the sky with respect to the background stars. This point is called the Winter Solstice. During the day that the Sun reaches this point, your noontime shadow is longer than any other day of the year. Also, the Sun spends less time in the sky on the day of the Winter Solstice than any other day making this the shortest day of the year. Even though it is the shortest day of the year, it is not the day with the latest sunrise or the earliest sunset. The latest sunrise is during the first week in January and the earliest sunset is during the second week in December. The Sun is at its southernmost point with respect to the background stars on the day of the winter solstice. This means the Sun spends the least amount of time above the horizon on that day. But, the Sun rise and set time depends on more than its apparent vertical motion. It also depends on where the Sun is on the analemma, that skinny figure-8 you see on globes and world maps. During the second week in December, the Sun is not quite to the bottom of the analemma. But, it is on the first part of the analemma to go below the horizon. During the first week in January, it is on the last part of the analemma to rise above the horizon. For more information on this, go to http://goo.gl/KpbkTf.
Tuesday: At 7 a.m., bright Venus is two fists above the southeast horizon, Mars is three and a half fists above the south horizon, and Jupiter is more than four fists above the south-southwest horizon.
Wednesday: What would that special someone want to see on the back of Santa’s sleigh when she gets up early Christmas morning to eat one of Santa’s cookies? A fruit cake? No. A barbell? Maybe to work off the fruitcake. A subscription to The Daily Record? Of course. But what she really wants is a ring. And if she looks out a south-facing window, she’ll see her ring. Saturn the ringed planet, that is. Saturn is about a half a fist above the southeast horizon at 7 a.m.
Thursday: Tonight’s late night full moon is in the constellation Orion. Tonight’s other Moon is…. Wait a minute. The Earth has only one Moon. True. And it has always had only one Moon. Not necessarily true. According to the best existing model, about four billion years ago, a Mars-sized object collided with the young Earth. The resulting debris coalesced to form the Moon. However, this model left a mystery: why is the Moon so asymmetric? Hardened-lava lowlands dominate the near side while the far side is dominated by mountainous highlands. According to a recent revision of the prevailing model, the early collision formed a large Moon and a small Moon. Over the years, the small Moon caught up to and collided with the large Moon. The highlands are the material from the collided small Moon. For more information about this theory, go to http://goo.gl/O801zk.
Friday: Where is the one who has been born King of the Jews? We saw Jupiter being eclipsed by the Moon in the east and have come to worship him” (Matthew 2:2, Bruce Palmquist version, informed by Michael Molnar). There are many theories as to the physical explanation of the Star of Bethlehem, the celestial object that guided the wise men to the location of Jesus. Some people think it was a recurring nova, a star that explodes. Some think it was a close alignment of bright planets. Some think it was a miracle that requires no physical explanation. In 1991, astronomer Michael Molnar bought an ancient Roman Empire coin that depicted a ram looking back at a star. Aries the ram was a symbol for Judea, the birthplace of Jesus. The Magi, or “wise men”, who visited the baby Jesus practiced astrology and would have been looking in that region of the sky for the king prophesied in the Old Testament. Molnar, a modern day wise person, used sky simulation software to model the positions of planets and the Moon in the region of Aries. According to his model, Jupiter was eclipsed, or blocked, by the Moon on the morning of April 17, 6 BC. A book written by the astrologer of Constantine the Great in 334 AD supports Molnar’s theory. The book describes an eclipse of Jupiter in Aries and notes a man of divine nature born during this time. See http://www.eclipse.net/~molnar/ for more information.
The moon, Aries, and Jupiter make an appearance in the Christmas sky tonight. The moon rises a little after 5 pm. At 8 p.m., the dim constellation Aries is six and a half fists above due south. Jupiter is about one above the east horizon just before midnight.
The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.