Wednesday, September 10, 2014
The Ellensburg sky for the week 9/13/14
Saturday: “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: Aldebaran, in the constellation Taurus, is about one fist held upright and at arm’s length above the east-northeast horizon at 11:30 p.m.
Monday: The last quarter moon rises a little before midnight and is in the constellation Taurus, moving into Orion by the morning.
Tuesday: At 8 p.m., Saturn is one fist above the west-southwest horizon. It seems to be having a carefree existence in the constellation Libra. Mars, on the other hand, is being forced to spend time with its rival in the constellation Scorpius. Because the brightest star in Scorpius was a similar color and brightness as Mars, it was given the name Antares which means “rival to Ares”, the Greek god of war. Since Mars was named after the Roman god of war, Antares can also be interpreted to mean “rival to Mars”. They are close together in the sky tonight and for the next two weeks. Both are about one fist above the south-southwest horizon. Mars is the brighter of the two and is slightly redder than Antares. Mars is also farther west, closer to Saturn.
Wednesday: 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 four fists above the southwest horizon at 8 p.m.
Thursday: “One world, group hug, love everyone” philosophy: political borders are human-made and can’t be seen from space. Real world, pragmatic discovery: some human-made political borders CAN be seen from space. Since 2003, India has illuminated its border with Pakistan to prevent illegal crossings. In August, astronaut Ron Garan took a picture of the boarder from the International Space Station. For more information, including the photo, go to http://goo.gl/mY8xG.
Friday: Jupiter is less than a fist above the waning crescent moon. The bright star Regulus is about a fist and a half to the lower left of the moon.
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.