Thursday, December 21, 2017
The Ellensburg WA sky for the week of 12/23/17
Saturday: I know you’re staying up late to train yourself to wait up for Santa. So look out a south-facing window at 12:30 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: The autumn star Fomalhaut is one fist above the south-southwest horizon at 6 p.m. It is getting ready for its winter nap.
Monday: 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 https://goo.gl/SwkLcL for more information.
The moon, Aries, and Jupiter make an appearance in the Christmas sky. At 7 a.m., Jupiter is two fists above the southeast horizon. At 8 p.m., the dim constellation Aries is six and a half fists above due south and the moon is three fists above the southwest horizon.
Tuesday: Is your favorite someone lamenting that she didn’t get that space-related calendar that she wanted? Are you sad that you ran out of money and can’t fulfill her last-minute wish? Worry not. The Jet Propulsion Laboratory has a free calendar summarizing much of the work that it has done. Download the calendar at https://goo.gl/hFu1UB.
Wednesday: Did you get a new telescope for Christmas? Skyandtelescope.com has a good article on how to get started using it. Go to https://goo.gl/c8fol5. Any observing tip about the night sky should include Mars. Even a small telescope will enable you to see how the angular size of Mars changes drastically from when Earth and Mars are far apart, as they are now, to when they are close together, as they will be in July of 2018. In fact, in July of 2018, Mars will be closer to the Earth than any year since 2003. Mars is two and a half fists above the south-southeast horizon at 7 p.m.
Thursday: Mercury is a good small telescope target when it far enough from the Sun in the sky, as it is this morning at 7 a.m. when it is a little less than a fist above the southeast horizon.
Friday: You’ve heard the term “a pinch to grow an inch.” Come on. Now I know you have. While there is no pinching involved, the distance between the Earth and moon increases by about an inch a year. Does it look farther tonight than when you looked at it on Monday? It’s 4/365ths of an inch farther from the Earth.
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 https://nightsky.jpl.nasa.gov/planner.cfm.