The Ellensburg sky for the week of 2/15/14

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: Headline from the tabloids: Earth sends robot to Mars in order to take a selfie. In January, the Mars Curiosity rover took a picture of its night sky that included the Earth and moon. Both would easily be visible to the naked eye for a human standing on Mars. Since you can’t go to Mars, go to http://goo.gl/DqprKF look at the picture.

Monday: Jupiter is six and a half fists above the south horizon at 6 a.m.

Tuesday: “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, at that time classified as the ninth planet. However, as astronomers started discovering a lot of similar objects in that part of the solar system, they realized that had a classification crisis on their hands. Should everything in this region of the solar system be named a planet? Eventually the International Astronomical Union (IAU) reclassified Pluto and all future Pluto-like objects as dwarf planets. According to his wife, if Mr. Tombaugh were alive today, he maybe disappointed at the reclassification but he’d accept it because, as a scientist, he’d recognize the implications the new naming scheme would have on future discoveries. Besides, noted astronomer Hal Levison, while Tombaugh didn’t discover the ninth planet, he discovered the Kuiper Belt and that’s a whole lot more interesting.

Wednesday: Spica is less than a finger width to the left of the moon in the southwest sky at 6 a.m. Mars eyes them warily from above.

Thursday: Along with Pluto, Tombaugh discovered numerous asteroids, variable stars, and star clusters. Up until recently, the responsibility of naming all of these objects would have belonged to the International Astronomical Union. But last summer, the IAU revised their naming rules to let individuals suggest names for certain celestial objects. For more information about this change, go to http://goo.gl/91fddH.

Friday: After visiting Mars and Spica Wednesday morning, the moon has shifted eastward in the sky and is about a half a fist to the right of Saturn in the southern sky at 6 a.m.

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.