Wednesday, December 24, 2008

The Ellensburg sky for the week of 12/27/08

Saturday: 2009 has been proclaimed the International Year of Astronomy (IYA) by scientific organizations all over the world. Why 2009? It is the 400th anniversary of Galileo first using a telescope to study the sky and of the publication of Astronomia Nova, Kepler’s ground breaking book about the motion of the planets. You can find information about IYA activities at http://astronomy2009.us/. My favorite IYA website is http://astronomy2009.nasa.gov/, NASA’s effort to educate us about all aspects of astronomy. Each month, NASA has picked a “Hot Topic” and something to “Go Observe!”. January’s hot topic is telescopes and space probes. The planet Venus leads off the year as the first object to observe. Venus holds a special place in the history of astronomy as being the first object, other than the Moon, to be observed to go through phases. The specific pattern of phases, first observed by Galileo, provides evidence that the Earth is not at the center of the Solar System. Stay tuned to this space about IYA events in Ellensburg.

Sunday: Saturn is one fist held upright and at arm’s length above due east at 11:30 p.m. What does it mean to be “one fist held upright and at arm’s length above due east?” Make a fist with your right hand. Hold it out in front of you at arm’s length. Do you feel like you can “fight the power”? Good. Now, hold your fist vertical so your thumb is on top. The angular distance from the top of your fist to the bottom is 10 degrees. Place the top part of your fist at eye level. This represents zero degrees. Now, stack the left fist on top. The top of this fist is 10 degrees above the horizon. Any celestial object even with the top of your left fist is about 10 degrees above the horizon. If you were to hold your left fist steady and move your right fist on top of the left, the top of the right fist would be about 20 degrees above the horizon.

Monday: Jupiter is about a half a fist above the southwest horizon at 5:15 p.m. Mercury is about a finger’s width to the lower left of Jupiter.

Tuesday: Antares is about a half a fist above the southeast horizon at 7 a.m.

Wednesday: Forget about that big bright ball in Times Square. You can mark the start of the new year with one of the sky’s own big bright balls. That perennial favorite New Year’s Day marker, Sirius, the brightest star in the night sky, rises to its highest point in the sky a little after midnight on January 1. Thus, when Sirius starts to “fall”, the new year has begun. Look for Sirius about two and a half fists above due south at midnight.

Thursday: Today is the day we celebrate something new – a new classification of celestial objects. Giuseppe Piazzi discovered Ceres [pronounced sear’-ease], the first of what are now called “asteroids”, on January 1, 1801. Ceres is the largest asteroid in the belt between Mars and Jupiter. At first, Piazzi thought it was a star that didn’t show up on his charts. But, he noted its position changed with respect to the background stars from night to night. This indicated to him that it had to be orbiting the Sun. August 2006, Ceres got promoted to the status of “dwarf planet” by the International Astronomical Union.

Friday: Tonight’s weather forecast: showers. Meteor showers, that is. The Quadrantid meteor shower peaks tomorrow morning making tonight and tomorrow the best night to see meteors. Meteor showers are named after the constellation from which the meteors appear to originate. That makes this shower mysterious because there isn’t any constellation with this name now. The shower was named after Quadrans Muralis, an obsolete constellation found in some early 19th century star atlases. These meteors appear to come from a point in Draco the dragon. This point is about three fists above the northeast horizon at 1 a.m. In good years, careful observers can spot about 100 meteors per hour. This could be a good year because the waxing crescent moon sets at 11:30 p.m. meaning the prime viewing time will be moon free. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere. Most meteors are associated with the path of a comet. This shower consists of the debris from an asteroid discovered in 2003.

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

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 http://aa.usno.navy.mil/faq/docs/dark_days.html.

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 http://www.eclipse.net/~molnar/ 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.

Wednesday, December 10, 2008

The Ellensburg Sky for the week of 12/13/08

Saturday: The Geminid meteor shower peaks late tonight and early tomorrow morning. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Gemini the twins. This point is about three fists held upright and at arm’s length above the east-northeast horizon at 9 p.m. tonight. You can follow this point throughout the night as it will remain near the bright star Castor, the right hand star of the “twin” stars Pollux and Castor. This shower is typically one of the best ones of the year producing bright, medium speed meteors with about 50 meteors per hour near the peak. Most of the dim meteors in the sky tonight and tomorrow morning will be obscured by the light of the waning gibbous moon.
Most meteor showers occur when the Earth passes through the orbital trail of a comet. The broken off comet fragments collide with the earth and burn up in the atmosphere. Astronomers had searched for the comet source since 1862 when the shower was first observed. In 1983, astronomers discovered the object that created the fragments that cause the meteor shower. To their surprise, it was a dark, rock that looked like an asteroid, not a shiny icy comet. Astronomers named this object Asteroid 3200 Phaethon. But, they still don’t know if it an asteroid or if it is a comet with all of its ice boiled off by many close passes by the Sun.

Sunday: Jupiter is rapidly fading toward the southwest horizon. The much brighter planet Venus is to the upper right of Jupiter. Venus is most likely the first object you’ll find in the southwest sky because it is the brightest point of light in the sky. It is a fist above the southwest horizon at 6 p.m. Jupiter is nearly a fist to the lower right of Venus.

Monday: Who could forget this holiday classic? “Away in the manger, no crib for its bed. The Moon near Praesepe in Cancer instead.” Oh. You have forgotten it already. Well, that’s probably for the better. At least this song has meaning this morning because the Moon is in the constellation Cancer near the open star cluster called Praesepe (Latin for “manger”). Watching over the manger are Asellus Borealis and Asellus Australis, the northern and southern donkey stars, respectively. The donkeys and the manger are less than a fist to the upper left of the moon, too dim to be seen with the naked eye through the glare of the Moon.

Tuesday: When you were growing up, you may have heard “Don’t make waves.” The red supergiant star Betelgeuse must not have listened. According to data from the Japanese Akari satellite, Betelgeuse creates a shockwave as it moves through the surrounding cloud of gas and dust. If viewed through a telescope sensitive to infrared radiation, this shockwave would appear to be the size of the full Moon as seen from Earth. Betelgeuse is four fists above the southeast horizon at 10 p.m.

Wednesday: Capella, the bright star in the constellation Auriga the charioteer, is straight overhead at 11:30 p.m.

Thursday: Saturn is about a fist to the upper left of the Moon this morning. They are four fists above the south-southwest horizon at 7 a.m.

Friday: This morning’s last quarter moon is in the constellation Virgo.

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

Wednesday, December 3, 2008

The Ellensburg Sky for the week of 12/6/08

Saturday: The earliest sunset of the year occurs this week. 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.

Sunday: “Hey baby! What’s your sign?”
“Ophiuchus, of course”
The Sun is in the same part of the sky as the stars of Ophiuchus from about November 29 to December 17. This is what astrologers mean when they say the Sun is “in” a constellation. Thus, if you were born between these dates, you should be an Ophiuchus. The fact that the horoscopes never list Ophiuchus is a major flaw of astrology. Astrology says that some of our characteristics are based on the location of the Sun at our birth. How can astrologers leave out three weeks from their system? That is like a scientist saying she can explain the results of her experiment every month of the year except early December. Ophiuchus was a mythical healer who was a forerunner to Hippocrates. According to myth, he could raise people from the dead. Maybe that is why he is ignored by astrology. Raising people from the dead is much less impressive than giving highly personal advice such as “Today is a good day to watch your finances.”
The bright stars of Ophiuchus rise just before the Sun. Rasalhague (pronounced Ras’-al-hay’-gwee), the brightest star, is about one fist held upright and at arm’s length above the east horizon at 6:30 a.m.

Monday: Venus is about a fist above the southwest horizon at 6 p.m. Jupiter, about one fifth as bright, is less than half a fist to the lower right of Venus.

Tuesday: Saturn rises at about midnight. By 6 am, it is nearly five fists above due south.

Wednesday: At about 11 p.m., the Moon occults the Pleiades. That means the Moon passes between the open star cluster called the Pleiades and the Earth, blocking the light of the Pleiades from reaching Earth. They are six and a half fists above the south-southwest horizon when this happens.

Thursday: Sirius, the brightest star in the nighttime sky, is one fist above the southeast horizon at 10 p.m.

Friday: In 1981, the well known astronomy rock group Blondie released The Tide is High in two versions: the radio version and the astronomy version. In the astronomy version, Debbie Harry sang: “The tide is high ‘cause the moon is full. Higher still when the moon’s close, Will.” (Will must be Debbie’s sky watching partner.) The full moon is the phase where the Moon is on the opposite side of the Earth from the Sun. That means the moon and Sun are both stretching the Earth in the same direction causing the ocean water in line with the Sun and moon to be pulled upward. The highest high tides occur when the moon is full or new. In addition, the moon is at perigee this evening. Peri- means close and –gee refers to the Earth so this is the day of the month when the moon is closest to the Earth. This accentuates the upward pull on the water and makes the tides really high.

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