Thursday, February 17, 2022

The Ellensburg, WA sky for the week of February 19, 2022

Saturday: Tonight is a great night to look for the Big Dipper. Tomorrow will be a great night to look for the Big Dipper. In fact, every night for many centuries will be great nights to look for the Big Dipper. But the Big Dipper’s shape slowly changes over many, many, many, many centuries. (Have I reached my word count yet?) Tens of thousands of years ago, it didn’t look like a dipper and tens of thousands of years from now, it will no longer look like a dipper. For a short video simulation of the changing Big Dipper, go to https://youtu.be/txJH8RlIoXQ. For a look at the current Dipper, face northeast at 8:00 p.m. The lowest star, Alkaid, is two fists held upright and at arm's length above the horizon. 

Sunday: The moon is a half a fist above the east-southeastern horizon at 11:00 p.m. The bright star Spica is a little over a half a fist to the upper right of the moon.

Monday: Last week we learned that Clyde Tombaugh discovered the first planet 9. Will you discover the new Planet 9? You and thousands of others will have the opportunity to comb through images of the sky from NASA’s Wide-field Infrared Survey Explorer (WISE). You’ll view short “flipbook” movies of the same patch of sky on different nights. Any point of light that moves could be Planet 9 or another undiscovered Solar System object. Read about how you can join the search for Planet 9 at http://tiny.cc/fh4jtz.    

Tuesday: Very bright Venus is nearly one and a half fists above due southeast at 6:15 a.m. Mars is halfway between Venus and the horizon. Mercury is just above the east-southeastern horizon.

Wednesday: 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. Look for the ghostly patch after twilight for the next few weeks.

Thursday: On these late winter mornings, it is still difficult to get going. You just want to plop into a chair and sit still. But, are you really sitting still? You’re moving at about 700 miles per hour due to the rotation of the Earth on its axis and 66,000 miles per hour due to the revolution of the Earth around the Sun. If that’s not enough, the entire solar system is orbiting the center of the galaxy at a whopping 480,000 miles per hour! So while you may be sitting still with respect to your living room (and all of the overachievers in your house), you are NOT sitting still with respect to the center of the galaxy. For more information about this concept, go to https://nightsky.jpl.nasa.gov/docs/HowFast.pdf

Friday: Two bright stars, Vega and Deneb, are hugging the northern horizon together at 11:00 p.m. Vega, the brighter of the two, is about a half a fist above the northeastern horizon. Supergiant Deneb to two and a half fists to the left of Vega, closer to due north.


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.

Saturday, February 12, 2022

The Ellensburg, WA sky for the week of 2/12/22

 Today: On February 18, 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 they 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. This week you can celebrate the discovery with the people at Lowell Observatory, the “home” of Pluto’s discovery. Go to https://iheartpluto.org/ for more information about nightly events from tonight through February 21.

Sunday: Are you going to watch the super bowl tonight? Is the bowl really that super? After all, half the night the bowl is tipped upside down, spilling out all of its contents. But don’t just focus on the functionality of the bowl. Think about how it inspires people all across the world to look at the night sky. In Mongolia, participants in the super bowl are known as gods. An Arabian story says the super bowl is a coffin. I encourage you to go outside tonight at about 8:00 p.m., after whatever unimportant thing you have been doing since 3:30 p.m. Look low in the north-northwestern sky and watch the super bowl, also known as the Big Dipper, balancing on the end of its handle, proudly displaying its large bowl.

Monday: Next Monday on President’s Day, let’s remember Abraham Lincoln: 16th president, country lawyer, man on the penny, wrestler, 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 (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. For more information about Lincoln’s “almanac trial”, go to http://goo.gl/r83q4X

Tuesday: Jupiter is a half a fist held upright and at arm’s length above the west-southwest horizon at 6:00 p.m.

Wednesday: The good news is the days are getting longer and the nights are getting shorter. The better news for most readers of this column is the farther north you go in the United States, the longer the days get. Here in Ellensburg, there are almost two more hours of daylight than on the first day of winter. In the southern part of the US, there is only 50 more minutes of sunlight. If you’d like to have your own fun with day lengths and other time questions, go to https://www.timeanddate.com/sun/.

Thursday: At 6:15 a.m., Venus is a little more than one fist above the southeastern horizon. Mars is about a half a fist below it. Mercury is much more challenging to see, just above the horizon to the lower left of the other two planets.

Friday: The sky is so wondrous. It makes me want to sing. Who can forget that memorable song by Three Dog Constellations Night, “The sky is black. The stars are white. Together we learn to find the light.” Well, maybe it didn’t go like that. Which is good. Because not all stars are white. Most stars are too dim to notice a color. But, two of the stars in the constellation Orion provide a noticeable contrast with each other. Betelgeuse, five fists above due south at 8:30 p.m. is a red giant. Rigel, the bright star about two fists to the lower right of Betelgeuse, is a blue giant.

By the way, the three dog constellations are Canis Major, the greater dog, found one and a half fists to the lower left of Orion; Canis Minor, the lesser dog, found two and a half fists to the left of Betelgeuse; and Canes Venatici, the hunting dogs, found low in the northeast sky, halfway between the Big Dipper and the horizon. Canis Major contains Sirius, the brightest star in the nighttime sky.

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.