The Ellensburg sky for the week of 2/16/13

Saturday: This President’s Day weekend, let’s remember Abraham Lincoln: 16^th president, country lawyer, man on the penny, vampire hunter, and astronomer. Vampire hunter? No. 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 (sic). 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 rising and setting times for August 29, 1858 as evidence in a trial. This is one of the earliest uses of forensic astronomy. 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://goo.gl/dS56e.

Sunday: Throughout the night, Jupiter will be near the first quarter moon in the night sky. At 8 p.m., they are five and a half fists above the southwest horizon, with Jupiter being about a half a fist to the upper left of the moon. As the night goes on, the moon moves closer to Jupiter. When the moon sets a little after 1 a.m., there are barely two finger widths between the two.

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

Tuesday: Along with Pluto, Tombaugh discovered numerous asteroids, variable stars, and star clusters. But he never discovered a moon. Of course, neither have you. But you do have the opportunity to help name two of Pluto’s moons. Go to http://www.plutorocks.com/ to cast your ballot. (I apologize to you Galileo, if you are reading this from you time machine, because you actually did discover four moons.)

Wednesday: Regulus, the bright star in the constellation Leo the lion, is nearly two fists above due east at 7 p.m.

Thursday: I hope you got your sweetie something red for Valentine’s Day last week. If not, I suggest a nice picture of the Red Valley on Mars. This January, the Mars Express probe took the first high-resolution stereo color image of Tinto Vallis, or Red Valley, the mouth of an ancient water flow on Mars. For more information and many photos of Tinto Vallis, go to http://goo.gl/ptJcr. Mars, itself, is too close to the Sun to be visible in the night sky.

Friday: Saturn is a half a fist above the east-southeast horizon at midnight.

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