Thursday, May 31, 2018

The Ellensburg WA sky for the week of 6/2/18

Saturday: The CWU Physics Department and the College of the Sciences is hosting its First Saturday Planetarium Show today from noon to 1 pm. Local science educator Megan Rivard will give a kid-friendly presentation about what can be seen in the summer sky called "Summer Night Lights – A Tour". 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 

Sunday: Cygnus the swan flies tonight. Deneb, the brightest star in the constellation, whose name means “tail” in Arabic, is two and a half fists held upright and at arm's length above the northeast horizon at 10 p.m. Cygnus’ wings make a vertical line one half a fist to the right of Deneb. Its head, marked by the star Albireo, is two fists to the right of Deneb. While Deneb is at the tail of Cygnus, it is at the head of the line of bright stars. It is 160,000 times more luminous than the Sun making it one of the brightest stars in the galaxy. It does not dominate our night sky because it is 2,600 light years away, one of the farthest naked eye stars. If Deneb were 25 light years away, it would shine as bright as a crescent moon. Compare that to Vega, which is 25 light years away. Vega is three and a half fists above the east-northeast horizon at this time. 

Monday: Venus is one and a half fists above the west horizon at 9:30 p.m. 

Tuesday: While the NASA probe Dawn is off exploring the largest main-belt asteroid Ceres, you can explore the second largest asteroid Vesta. NASA has released Vesta Trek, a free web-based application that allows you to zoom in, “fly” over the surface, measure craters sizes, and see what Vesta looks like in different wavelengths of light. Go to for more information about Vesta Trek and the Dawn mission. Vesta is the brightest asteroid and can easily be seen with binoculars. For the next few weeks, use Saturn as your celestial starting point. Find Saturn with your binoculars, a little more than one fist above the southeast horizon at midnight. Shift your binoculars so Saturn is in the lower left edge of your field of view. Move your binoculars a little to the upper right. The brightest point of light in the region of the sky you are now looking at is Vesta. To confirm, go back to that spot for the next few nights. Vesta will move noticeably from night to night with respect to the background stars. 

Wednesday: As the weather warms up, people start thinking about swimming in a nice cool body of water. Recently, astronomers have discovered evidence an ocean about 20 miles beneath the surface of Saturn’s moon Enceladus. NASA’s Cassini probes measured variations in how the moon’s gravity pulled on the orbiting spacecraft. These variations can be explained by a large amount of liquid water under one section of the ice because liquid water is denser than an equal volume of ice. While you need a very large telescope to see Enceladus, Saturn is one fist above the southeast horizon at 11:30 p.m. 

Thursday: Jupiter is two and a half fists above due south at 10:47 pm. That is as high as it will get above the horizon this season. 

Friday: Mars is two fists above due south at 4:30 a.m. I know, you may still be sleeping. But your co-worker isn't so she will soon pass you in the race to the top of the career ladder! And, she will see Mars. 

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 

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