Monday, February 23, 2009

The Ellensburg sky for the week of 2/28/09

Saturday: If the National Enquirer was around in Galileo’s day, it may have featured the headline: “Saturn has love handles; Opis leaves him for a much thinner Mars”. When Galileo first observed Saturn through a telescope, he reported objects that looked like bulges on either side of Saturn’s midsection. He was actually seeing Saturn’s rings through less than ideal optics. Go to http://astronomy2009.nasa.gov/observe.htm for more information about Saturn. Go to three and a half fists held upright and at arm’s length above the southeast horizon at 10 p.m. to see Saturn.

Sunday: March’s “Hot Topic” for the International Year of Astronomy is observing at night… and in the day. Technology has expanded the amount of information astronomers can learn from observing the sky. Up until the mid 1900s, we studied the sky using a very narrow portion of the electromagnetic spectrum – visible light waves. It was like studying music by listening only to notes of medium pitch. The invention of the radio telescope opened up a new source of information, long wavelength radiation. It also opened a new time to observe the sky – the day time. Radio waves from outer space are not blocked by the sunlit sky like visible light from outer space is. Since then, astronomers have started gathering gamma ray, x-ray, ultraviolet, infrared, and microwave radiation. Finally, the entire symphony rather than a few notes. But technology has also negatively impacted our view of the nighttime sky through light pollution. The dim light of a distant galaxy is facing more and more competition from businesses that use inefficient lighting that lights the sky as much as it lights the ground. Many communities, including Ellensburg, have passed or are working on ordinances to reduce this costly and sky-robbing stray lighting. Go to http://astronomy2009.nasa.gov/topics.htm for more information about the March “Hot Topic”.

Monday: It’s getting dark. The last remnant of twilight has disappeared. Suddenly, you notice a large softly radiant pyramid of light in the western sky. The base of this ghostly triangle is along the west horizon and the peak stretches two or three fists above the horizon. It is not really a ghost. It is an effect called the zodiacal light. This light comes from sunlight reflecting off dust grains in our solar system. The effect is the most visible when the band of constellations called the zodiac makes a steep angle with the horizon. You need a clear dark sky with no haze or light pollution to see the zodiacal light. At its brightest, the zodiacal light rivals the light of the central Milky Way.

Tuesday: Tonight’s first quarter moon is in the constellation Taurus the bull.

Wednesday: “The crow rises in the southeast” said spy number one. “I’m sorry. I don’t recognize that code” replied spy number two. Spy one exclaimed, “That’s because it’s not a code, you idiot. I’m talking about the constellation Corvus the crow.” This is very bad spy movie dialogue to remind you that Corvus had a very bad life. According to one myth, Corvus brought the god Apollo the news that his girlfriend was seeing someone else. In a classic case of punishing the messenger, Apollo turned the formerly beautifully colored crow black. The box-shaped Corvus is one fist above the southeast horizon at 11 p.m.

Thursday: Venus is two fists above due west at 7 p.m.

Friday: Jupiter is less than a half a fist above the east-southeast horizon at 6 a.m.

The positional information in this column about stars and planets is typically accurate for the entire week.

Thursday, February 19, 2009

The Ellensburg sky for the week of 2/21/09

Saturday: In this, the 200 anniversary of the year of his birth, let’s remember Abraham Lincoln: 16th president, person on the penny, and astronomer. Astronomer? Well, maybe not an astronomer, but someone who used observational evidence from the sky to solve a problem. In 1858, Lincoln defended Duff Armstrong, a family friend who was accused of murder. The prosecution thought they had a strong case because their primary witnesses claimed to have observed the killing by the light of the nearly full moon. Let’s listen in on the trial courtesy of the 1939 film, Young Mr. Lincoln.
Lincoln: How’d you see so well?
Witness: I told you it was Moon bright, Mr. Lincoln.
Lincoln: Moon bright.
Witness: Yes.
(Dramatic pause as Lincoln reaches for something)
Lincoln: Look at this. Go on, look at it. It’s the Farmer’s Almanack. You see what it says about the Moon/ That the Moon… set at 10:21, 40 minutes before the killing took place. So you see it couldn’t have been Moon bright, could it?
Lincoln used the known information about Moon rise and set times for August 29, 1858 as evidence in a trial. You may confirm Lincoln’s findings on the Moon set time by going to http://aa.usno.navy.mil/data/docs/RS_OneYear.php, the US Naval Observatory website, and filling out Form A. For more information about Lincoln’s “almanac trial”, go to http://media.skyandtelescope.com/documents/Almanac_Trial.pdf.

Sunday: The region in the low southeastern sky around the Moon is crowded with three planets this morning. Mercury is just to the left of the Moon. To the left of Mercury is the brightest of the three planets, Jupiter. Mars is to the lower left of Jupiter. You may need binoculars to see all three at 6:30 a.m. If this morning is cloudy, keep inspecting this part of the dawn sky for the next few days. The Moon will have moved away but the planets will remain clumped together.

Monday: Comet Lulin, discovered in July 2007, is just below Saturn tonight. Grab your binoculars and look three fists held upright and at arm’s length above the southeast horizon at 10 p.m. Saturn is the brightest point of light in that region of the sky. Comet Lulin will be an elongated smudge just below it.

Tuesday: 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.

Wednesday: Sirius, the brightest star in the nighttime sky, is two and a half fists above the south horizon at 9 p.m.

Thursday: The bright star Arcturus is two and a half fists above due east at 11 p.m.

Friday: Venus is about a finger’s width to the right of the young crescent Moon. At 7 p.m., they are two fists above the west horizon. Venus is in the western evening sky the entire week.

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

Wednesday, February 11, 2009

The Ellensburg sky for the week of 2/14/09

Saturday: According to Greek mythology, the beautiful princess Andromeda was chained to a rock next to the ocean. Cetus the sea monster was about to devour her in order to punish her family. It seemed that all was lost. But, along came the great warrior Perseus, fresh off his defeat of the evil Gorgon, Medusa. The only similarity between Andromeda and Medusa was that Andromeda caused people to stand still and stares at her beauty while Medusa turned people to stone because of her ugliness. (And, you thought you looked bad in the morning.) Even though Perseus’ standing as the son of King Zeus and the slayer of Medusa was probably enough to win Andromeda under normal circumstances, Andromeda’s impending death-by-sea-monster was not a normal circumstance. So, Perseus drove his sword into the sea monsters neck and killed it. In a little known addendum to the story, Perseus carved “Percy (heart symbol) Andi” in the rock, thus originating the use of the heart symbol as a substitute for the word “love”.
You can find these lovers in the sky this Valentine’s Day. Just remember it is rude stare – and you never know when you might turn to stone. First, find the Great Square of Pegasus at 7 p.m. between one and a half and three and a half fists held upright and at arm’s length above the west horizon. The lowest star in Andromeda is the top star in the square. This represents Andromeda’s head. Perseus is at her feet, nearly straight overhead. Mirphak, the brightest star in Perseus is about eight fists above the west horizon. Perseus’ body is represented by the line of stars to the left and right of Mirphak.

Sunday: Comet Lulin, discovered in July 2007, is just above the bright star Spica for the next three mornings. Grab your binoculars and look two and a half fists above the southwest horizon at 6 a.m. Spica is the brightest star in that region of the sky. Comet Lulin will be an elongated smudge just above it.

Monday: Saturn is almost two fists above the east horizon at 9 p.m.

Tuesday: The bright star Antares is about a finger’s width to the left of the Moon at 6:30 a.m. They are due south at this time.

Wednesday: “Happy Birthday to you. Happy Birthday to you. Happy Birthday dear Pluto. Happy Birthday to you.” Clyde Tombaugh discovered Pluto, the solar system object formerly known as a planet, on this day in 1930.

Thursday: The calendar may say February, but the late night sky is starting to say “summer triangle”. Vega, the brightest star in the summer triangle rises at 10:30 p.m. By midnight, it is a little less than one fist above the northeast horizon. The Summer Triangle is a set of three stars that is visible high throughout most of the night in the summer sky.

Friday: Three planets crowd the morning twilight sky. From lower left to upper right, Mars, Jupiter and Mercury are less than a half a fist above the east-southeast horizon, just ahead of the rising Sun. You may need binoculars to pick them out of the glare.

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

Thursday, February 5, 2009

The Ellensburg sky for the week of 2/7/09

Saturday: Are you scared of snakes? Then don’t look due east at 6:30 p.m. The pentagon-shaped head of Hydra the water snack is about one fist held upright and at arm’s length above the east horizon. And, this is no ordinary water snake. It is the largest constellation in the sky, more than twice the size of Orion. Hydra’s tail does not rice until after midnight.

Sunday: Tonight and tomorrow morning’s full moon is in the constellation Leo the lion. Because February is typically the snowiest month, some Native American tribes in the northeastern United States called the full moon in February the Full Snow Moon. Some tribes referred to how the harsh winter conditions affected their food gathering ability by calling the February full moon the Full Hunger Moon. The name Full Hunger Moon is especially appropriate this month because Leo the lion seems to be stalking the moon throughout the night to hunt it down for food.

Monday: Regulus, the brightest star in the constellation Leo the lion is about a thumb width to the left of the Moon at 7 p.m. They are both low on the eastern horizon.

Tuesday: Hydra is not the only long, squiggly constellation in the sky. Draco the dragon wraps around the cup of the little dipper. The head of the dragon is one fist above due north at 7:30 p.m. Eltanin, the brightest star in the constellation, is at one corner of the trapezoid-shaped head of Draco. Eridanus the river starts next to Rigel, the bright star in the lower right corner of Orion, and meanders down below the south horizon. Rigel is three and a half fists above due south at 7:30 p.m. That means at 7:30 tonight, there are long, squiggly constellations in the lower northern, southern and eastern sky.

Wednesday: Saturn is less than a fist above the Moon at 6 a.m. They are about two fists above the west-southwest horizon.

Thursday: In the past decade or so, astronomers have discovered 339 planets orbiting stars other than our Sun. All of these exoplanets, as they are called, have been much larger than Earth, gas giants like Jupiter or Neptune. However, last week European scientists using the COROT telescope discovered a planet with a diameter less than twice that of Earth orbiting a Sun-like star. Before you pack your bags, please realize that this planet is so close to its star that it has an estimated surface temperature of greater than 2000 degrees Fahrenheit. It orbits a dim star in the constellation Monoceros the unicorn in the middle of the triangle formed by the stars Betelgeuse, Sirius, and Procyon. This star, too dim to be visible even with binoculars, is four fists above due south at 9 p.m. For more information, go to http://www.skyandtelescope.com/news/38820797.html

Friday: Mercury is less than a half a fist above the southeast horizon at 6:30 a.m. Over the next few weeks, Mercury will get higher and higher in the morning sky.

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