Tuesday, September 25, 2018

The Ellensburg WA sky for the week of 9/29/18

Saturday: Mnemonics are helpful for remembering astronomy facts. (Similarly, “Johnny Mnemonic”, the 1995 cyberpunk film, was helpful in getting Keanu Reeves’ career going.) After all, school children all around the country are learning the order of the planets by remembering, “My very excellent mother just served us nine….” Oops, I guess that one needs updating. Well, here’s one that will not need updating for nearly 100,000 years: the order of the stars in the Big Dipper. Because the nighttime stars are so far away from us, their actual motion through the sky, called their “proper motion” is not noticeable over even thousands of years. That is why the constellations have remained the same since ancient times. But two stars in the Big Dipper have a proper motion large enough such than in 100,000 years; the stars will no longer make a dipper shape. Until then, you can remember the names of the seven dipper stars in order from handle to cup by remembering this helpful advice for teens: “AM, ask mom. PM, dad”. The stars are Alkaid, Mizar, Alioth, Megrez, Phad, Merek, and Duhbe. The Big Dipper is one fist held upright and at arm’s length above the north horizon at 11 p.m.

Sunday: The bright star Aldebaran is a half a fist to the lower right of the Moon. They are about six fists above the southern horizon at 6 a.m.

Monday: Jupiter is about one fist above the southwest horizon at 7:15 p.m.

Tuesday: Since Halloween is later this month; the stores are filled with bags of candy clusters. Instead, take time to look at a star cluster. The Hyades cluster is an open star cluster that represents the V-shaped face of Taurus the bull. It is one of the biggest and nearest star clusters with about 200 stars 150 light years away. The Hyades cluster was the first cluster to be the subject of detailed motion studies. These studies allowed astronomers to pinpoint the distance to the Hyades and provide important information about the scale of the universe. Aldebaran, nearly two and a half fistsabove the east horizon at midnight, is a foreground star and not a part of the Hyades cluster.

Wednesday: At 9 p.m., Saturn is one fist above the southwest horizon and Mars is two fists above due south.

Thursday: To the people of Ancient Greece, the stars that are about five and a half fists above the east-northeast horizon at 10 p.m. were known as Cassiopeia and Andromeda, a mythological queen and her daughter. But not all cultures imagined the same pictures in the sky. To the people of Polynesia, the stars of Cassiopeia and Andromeda represented a dolphin, called Kwu. Cassiopeia formed its tail, the brightest stars of Andromeda formed its fins, and its fainter stars outlined the dolphin’s body.

Friday: The CWU Physics Department and the College of the Sciences is hosting its monthly First Saturday planetarium show tomorrow from noon to 1 p.m. STEM Teaching major Katy Shain will give a presentation about the nighttime sky called “The sky, what is it good for? Absolutely everything.” The sky can’t tell you who to marry. But Katy will tell you about different ways civilizations have used the sky throughout history. The show is free and open to all ages. There will be a show at noon on the first Saturday of every month hosted by different CWU astronomers and astronomy educators. The planetarium is room 101 in Science Phase II, just off the corner of 11th and Wildcat Way, H-11 on the campus map found at https://www.cwu.edu/facility/campus-map.

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.

Friday, September 21, 2018

The Ellensburg WA sky for the week of 9/22/18

Saturday:  At precisely 6:54 p.m. PDT, the center of the Sun crosses the celestial equator and passes into the southern sky. The celestial equator is an imaginary line that divides the sky into a northern and southern half. When the Sun is in the southern half of the sky, it appears to take a shorter path from rising to setting. It also does not get as high in the sky at noon. This leads to shorter days and longer nights. Since the Sun crosses the celestial equator today, there is an instant when it is equally in the northern and southern sky, called the north and south celestial hemispheres. This so-called “equal night” is given by the Latin word equinox. Thus, today is known as the Autumnal Equinox. However, the day and night are not of equal duration today. The sun rises at 6:49 a.m. and sets at 6:59 p.m. in the northern latitudes of the United States. Day and night are closest to equal duration on Tuesday.

Sunday: Venus is at its brightest this week. But that doesn’t mean it is easy to see because it is very close to the horizon right after sunset. Try to spot it right above the southwest horizon right after sunset. Jupiter is a little bit higher, about a fist held upright and at arms length above due southwest at 7:15 p.m.

Monday: Shine on, shine on harvest moon, up in the sky. It’s just like a full moon in January, February, June and July. The only difference is that near the Autumnal Equinox (also known as the first day of fall), the full moon rises close to sunset resulting in a full night of light for the harvest. The harvest moon looks more orange than usual when it is near the horizon because of the dust kicked up from the harvest. The dust scatters the white light reflecting off of the Moon resulting in slightly more of the red and orange components of the white light reaching your eyes. Although the Moon has a dull yellow color whenever it is near the horizon owing to light scattering off of dust and atmospheric particles, the effect is more noticeable for the harvest Moon. For more information about the harvest moon, go to http://earthsky.org/space/harvest-moon-2

Tuesday: Stuart Sutcliffe was the fifth Beatle. d’Artagnan was the fourth Musketeer. Ophiuchus is the thirteenth constellation in the Zodiac. The Zodiac consists of all the constellations that the Sun appears to line up with as the Earth’s celestial perspective changes throughout its annual orbit. You know twelve constellations in the Zodiac because they are the 12 horoscope signs. But the Sun also lines up with Ophiuchus for about two weeks every year. You can spend some time with Ophiuchus tonight. The center of the coffin shaped group of stars is three fists above due southwest at 8:30 p.m.

Wednesday: Saturn is one and a half fists above the south-southwest horizon at 8:30 p.m.

Thursday: “There’s water in them thar craters”, frozen water, that is. There has been speculation since the 1960s and indirect evidence since the 2000s of water on the Moon. Recently astronomers studied data from the Moon Minerology Mapper, the Lunar Orbiter Laser Altimeter, Lyman-Alpha Mapping Project, and Diviner Lunar Radio Experiment. The light reflecting off the bottom of craters near the lunar South Pole showed characteristics of light reflecting off pure ice in their labs. The water likely came from comet impacts or other solar system objects with trace amounts of water ice. For more information this discovery, see https://goo.gl/P4zvtU.

Friday: Mars is two fists above due south at 9 p.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.

Sunday, September 9, 2018

The Ellensburg WA sky for the week of 9/15/18

Saturday: “You know Aries and Cancer and Draco and Libra. Leo and Pisces and Virgo and Hydra. But, do you recall, the pointiest asterism of all? Triangulum, the three sided asterism, had a very pointy edge….” Sorry. Some stores have started sending out their Christmas catalogues and that has put me in the mood to modify some Christmas songs. Anyway, Triangulum is a small constellation between the more prominent Andromeda and Aries. Its main feature is a skinny triangle oriented parallel to and nearly four fists held upright and at arm’s length above the east horizon at 11 p.m.

Sunday: Fomalhaut, the southernmost bright star visible from the northern USA, is one fist above the south-southeast horizon at 11 p.m. In 2008, Fomalhaut and its surroundings became the first star system with an extrasolar planet to be directly imaged  https://apod.nasa.gov/apod/ap081114.html.

Monday: At 8 p.m., Jupiter is one fist above the southwest horizon. Saturn is two fists above the south horizon and less than one fist to the left of the Moon.

Tuesday: The planet Neptune is on the opposite side of the Earth as the Sun is, meaning it is at its brightest and easiest to see. Of course, “bright and easy” is relative because you’ll still need binoculars to see it. First find Fomalhaut, the bright star a little less than one fist above the south-southeast horizon. Then move your binoculars up and to the left about three binocular fields of view to the fairly bright star called Skat. Next continue to move up and to the left about one and a half binocular fields of view to the reddish star called Hydor, which is a little dimmer than Skat. With Hydor in the upper right of your field of view, Neptune will be near the center. The radio program “Stardate” has three 1-minutes episodes about Neptune earlier this month. Listen to them here: https://stardate.org/radio/program/2018-09-05.

Wednesday: To celebrate the start of school at Central Washington University tomorrow, you could take a quick trip to Mars. How about America’s desert Southwest? Not enough time? Then just look at some photos from… from…. Hmmm. The photos at https://goo.gl/Elx7O8 look like they could be from either place. The Murray Buttes region of Mars, where the Curiosity rover has been exploring, look a lot like the landscape of Utah. So much so that the Mars-based movie John Carter was filmed there. Look for John Carter at your local video store. (“What’s that?” asked the child.) Look for Mars two fists above due south at 9:30 p.m., just a little bit below the Moon. If you wait until tomorrow night, the Moon will have moved eastward so you will be able to see Mars better.

Thursday: According to “One world, group hug, love everyone” philosophy, political borders are human-made and can’t be seen from space so why can’t we all just get along. According to real world, pragmatic discoveries, some human-made political borders CAN be seen from space. Since 2003, India has illuminated its border with Pakistan to prevent illegal crossings. In 2011, astronaut Ron Garan took a picture of that border from the International Space Station. For more information, including the photo, go to http://goo.gl/mY8xG.

Friday: Earlier this week, you read about Fomalhaut, the second brightest star with a planet. The brightest star with a planet is Pollux, in the constellation Gemini. (First and second brightest is misleading here because they are nearly identical in magnitude, 1.15 vs. 1.16.) Pollux is four and a half fists above due east at 5:30 a.m., right below its “twin” star Castor.  Read more about Pollux at https://goo.gl/cL5t9p.

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.

Friday, September 7, 2018

The Ellensburg WA sky for the week of 9/8/18

Saturday: Today: “Excuse me, do you have the time?”
“No, but the Big Dipper does.”
You can use the orientation of the Big Dipper to tell time with a precision of about 15-30 minutes. First, find the two stars at the far end of the Big Dipper cup, the stars that do not touch the handle. Draw an imaginary line segment starting at the North Star and passing through the two Big Dipper cup stars. Now, draw a big circle around the North Star. Your circle is a 24-hour clock. Number the circle from 0 hours at the top, counterclockwise to 12 hours at the bottom of the circle, and back up to 24 hours at the top. (O hours and 24 hours are the same on this clock because the day is 24 hours long.) The hour number on the big circle closest to where your imaginary line intersects this circle is called your raw time. Due to the location of the Big Dipper compared to the rest of the stars, the time nearest the intersection (the raw time) is correct for March 6. For any other night, subtract two times the number of months the current date is after March 6 from the raw time. For example, let’s say the imaginary line between the North Star and the Dipper stars is pointed to the right. That means the raw time is 18 hours or 6 p.m. If you made this observation on October 6, which is seven months after March 6, you would subtract two times seven or 14 hours from the raw time.  Thus, the time for November 6 is 18 hours minus 14 hours or 4 hours. In other words, 4 a.m. Don’t forget to convert for daylight savings time if needed. For a more complete explanation on how to do the Big Dipper clock math, go to http://goo.gl/02HmA. If you prefer a more visual tool, and a fun project to do with your kids, there is a simple “star clock” template and instructions at http://goo.gl/SFKrE. Use this paper star clock whenever you watch is broken.

Sunday: Jupiter is one fist above due southwest at 7:56 p.m. The bright star Antares is about two fists to the left of Jupiter, above the south-southwest horizon. Even though Antares is a supergiant, it still looks like a point through most telescopes. Most, but not all. Astronomers used the European Space Agency Very Large Telescope Interferometer to create an image of the surface of Antares. To see that image for yourself, go to https://goo.gl/Y4G4WF. To see Antares for yourself, look outside.

Monday: The calendar says summer is nearing an end. School starting says summer is nearing an end. The summer triangle in the sky begs to differ, as it is still high in the sky. Vega, the brightest star in the triangle, is a little bit south of straight overhead at sunset. Deneb is six and a half fists above the east horizon and Altair is five fists above the southeast horizon.

Tuesday: In 1987, the rock group Def Leppard sang “Pour some sugar on me, in the name of love. Pour some sugar on me, come on fire me up”. In 2012, some European astronomers “found some sugar near stars, they were very young. Found some sugar near stars, out where planets formed.” Astronomers observed molecules of glycolaldehyde, a simple form of sugar, in the disk of gas and dust orbiting young binary stars. This is the first time astronomers have found this simple sugar so close to a star indicating that organic molecules can be found in planet-forming regions of stars. For more information, go to http://goo.gl/tfwy1.

Wednesday: Venus and the bright star Spica are just above the west-southwest horizon at 8 p.m. They are between the waxing crescent moon and the horizon.

Thursday: Had the script been written a little differently for a well-known Robin Williams movie, we might have heard Mr. Williams shout, “Goooood Morning Orion the hunter”. Orion is typically thought of as a winter constellation. But, it makes its first appearance in the early morning summer sky. The lowest corner of Orion’s body, represented by the star Saiph (pronounced “safe”), rises at 2 a.m., well before the Sun. By 6 a.m., Orion’s belt is nearly four fists above the south-southeast horizon.

Friday: At 8 p.m., Saturn is two fists above the south horizon and Mars is one and a half fists above the south-southwest horizon.

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.