Thursday, December 18, 2008

The Ellensburg sky for the week of 12/20/08

Saturday: Have you ever looked down on the ground and spotted a penny? In Yakima? While you were standing in Ellensburg? If you have, then you’d be able to see the star Hamal is more than just a point of light. It has an angular diameter that can be detected from Earth. Hamal, the brightest star in the constellation Aries the ram, has the same angular diameter as a penny 37 miles away. (For comparison, the moon is about half the diameter of a penny held at arm’s length.) Hamal is six and a half fists held upright and at arm’s length above due south at 8 p.m.

Sunday: At 4:04 a.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 noon time 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

Monday: Venus is nearly two fists above the southeast horizon at 5:30 p.m.

Tuesday: What does that special someone deserve for Christmas? A dust mop? No. A bucket? No. A subscription to The Daily Record? No. Well, maybe. But what she or he really deserves is a ring. And, what better way to remember than to see the ringed planet. Saturn, the ringed planet, is a half a fist above due east at 11:30 p.m.

Wednesday: Mercury is barely above the southwest horizon at 5 p.m. It is about a half a fist to the lower right of the much brighter Jupiter

Thursday: 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). 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 man, 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. Molnar’s theory is supported by a book written by the astrologer of Constantine the Great in 334 AD. The book describes an eclipse of Jupiter in Aries and notes a man of divine nature born during this time. See for more information.
Aries and Jupiter make an appearance in the Christmas sky tonight. At 5:30 p.m., the dim constellation Aries is about five fists above the east-southeast horizon and Jupiter is a half a fist above the southwest horizon.

Friday: Tonight’s Moon is new. Don’t bother looking for it. The new moon is the phase where the Moon is directly between the Earth and the Sun. Hence the side of the Moon facing Earth is not receiving any sunlight and cannot be seen. In fact it is so well hidden, the icon on the Daily Record weather page says the new moon doesn’t occur until tomorrow. That is because the moon is directly between the Earth and Sun at 4:30 a.m. on December 27 making the night which includes December 26 and 27 the new moon night.

The positional information in this column about stars and any planet except Mercury is accurate for the entire week.

No comments: