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, the US Naval Observatory website, and filling out Form A. For more information about Lincoln’s “almanac trial”, go to

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.

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