The Ellensburg, WA sky for the week of November 23, 2019

Saturday:  Do you want to learn more about what goes on at night in the natural world? You can at a free event called Nature of Night on the CWU campus, today from 10 a.m. to 2 p.m. Go to the Science Building at the intersection of Wildcat Way and 11th Avenue, J-9 on the map found at http://www.cwu.edu/facility/campus-map. There will be 30 minute planetarium shows, fun nighttime projects, animals, cookies and much more. The CWU College of the Sciences is putting on this event. Go to cwu.edu/sciences for more information.

After you get home and have read about all of the interesting things you learned at Nature of Night, go outside at 5:00. Venus and Jupiter are a thumb width from each other in the sky, a half a fist held upright and at arm’s length above due southwest. Venus is the brighter of the two. They’ll be together for a few nights.

Sunday:  “Hey baby! What’s your sign?”

“Ophiuchus, of course”

The Sun is in the same part of the sky as the stars of Ophiuchus from about November 29 to December 17. This is what astrologers mean when they say the Sun is “in” a constellation. Thus, if you were born between these dates, you should be an Ophiuchus. The fact that the horoscopes never list Ophiuchus is a major flaw of astrology. Astrology says that some of our characteristics are based on the location of the Sun at our birth. How can astrologers leave out three weeks from their system? That is like a scientist saying she can explain the results of her experiment every month of the year except early December. Ophiuchus was a mythical healer who was a forerunner to Hippocrates. According to myth, he could raise people from the dead. Maybe that is why he is ignored by astrology. Raising people from the dead is much less impressive than giving spot-on advice such as “Today is a good day to watch your finances.”

The bright stars of Ophiuchus rise just before the Sun. Rasalhague (pronounced Ras’-al-hay’-gwee), the brightest star, is about a half a fist held upright and at arm’s length above the east-northeastern horizon at 6:30 a.m.

Monday: Are you thankful that you live in a solar system with multiple planets? You should be. A giant planet like Jupiter cleans up planetary debris that could have collided with Earth and hindered the formation of complex life. Any inhabitants of the planets orbiting Upsilon Andromedae are thankful for this, as well. Upsilon Andromedae, a star in the constellation Andromeda, was the first Sun-like star discovered to have multiple planets orbiting it. So far, all of its planets are giant planets like Jupiter. But, the system is likely to also contain smaller planets. The dim star, but certainly not its planets, is barely visible straight overhead at 9 p.m. Jupiter is still hanging out with Venus, low in the southwestern sky fight after sunset.

Tuesday: Mars is one and a half fists above the southeastern horizon at 6:30 a.m.

Wednesday: Mercury will be as far away from the Sun in the sky as it will get this orbital cycle. This "farthest away" point is known as the planet's greatest elongation. Since Mercury is in the morning sky, it is west of the Sun and this occurrence is called the greatest western elongation. This morning, Mercury is one fist above the east-southeastern horizon at 6:30 a.m. Over the next few weeks, Mercury will move toward the Sun in the sky. By early February, it will be visible in the evening sky.

Thursday: Some of us have a lot to be thankful for on Thanksgiving. But, probably not as much as Andromeda had to be thankful for. 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. Her mother Queen Cassiopeia and her father King Cepheus didn’t know what to do. It seemed that all was lost. But, along came Andromeda’s boyfriend, the great warrior Perseus. 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 monster’s neck and killed it. This was the first time in recorded history that a set of parents actually welcomed an uninvited Thanksgiving visit from the boyfriend. Perseus is about five fists above the east-northeast horizon and Andromeda is about seven fists above the east horizon at 7 p.m.

Also be thankful that (from left to right) the Moon, Venus, and Jupiter are neighbors in the southwestern sky right after sunset.

Friday: We are just a few days away from the earliest sunsets of the year in Ellensburg. (No, the earliest sunset is not on the first day of winter.) So this is a good time to learn how to quantify the darkness of the sky. First find the Great Square, the main part of the constellation Pegasus. It is six fists above due south at 7 p.m. Find the dimmest star that you can see inside or near the square. Then compare that star to the chart at  https://www.skyandtelescope.com/observing/how-dark-is-your-night-sky/. The larger the magnitude number, the dimmer the star. When the sky is exceptionally dark, you can see more stars and more interesting deep-sky objects such as star clusters and nebulae.

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.