The Ellensburg, WA sky for the week of August 1, 2020

Saturday:  The CWU campus is closed. But astronomy learning lives on! The Physics Department and the College of the Sciences is hosting a First Saturday VIRTUAL planetarium show today from noon to 1:00 p.m. CWU professor Bruce Palmquist will guide you through a short trip through the Solar System using Worldwide Telescope, using the Worldwide Telescope program found at http://worldwidetelescope.org/webclient/. Go to https://tinyurl.com/y6ojsez3 for registration information.

After the Sun sets, look to the southeastern sky to see Saturn about a half a fist held at arm’s length to the left of the Moon and Jupiter less than a half a fist above the Moon. If you look with a good pair of 10x50 binoculars, you may see the moons Ganymede and Callisto tucked in to the upper right of Jupiter. They’ll probably look like a single point of light.

Sunday: Comet NEOWISE is no longer visible to the naked eye. But it is still a splendid binocular object. At 10:00 p.m. tonight, it is nearly three fists held upright and at arm’s length above the western horizon and two fists to the lower right of the bright star Arcturus (which is four fists above the west-southwestern horizon). Comet NEOWISE is less than a first to the left of the Coma Star Cluster, an open star cluster about 280 light years from Earth.

Monday: The Perseid meteor shower peaks next week. But the Moon will be out during the peak late night/early morning times so it may be better to spread out your Perseid viewing this year. The meteors appear to come from a point just below the W of the constellation Cassiopeia. This point is about two and a half fists above the northeast horizon at 11 p.m. By dawn, this point is about seven fists above the northeast horizon. If you fall asleep or forget to set your alarm, you will be able to observe this shower from about 11 p.m. to dawn for the next two weeks in about the same location in the sky. The Perseid shower is one of the longest lasting showers. For tips about optimizing your viewing this year, go tohttps://earthsky.org/?p=165416  As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. These meteors are sand to pea-sized bits of rock that fell off of Comet Swift-Tuttle. They are traveling about 40 miles per second as they collide with the Earth and burn up in the atmosphere.

Tuesday: Venus is two and a half fists above the eastern horizon at 5:00 a.m. Mercury is a half a fist above the east-northeastern horizon at this time, rapidly moving towards the Sun in the sky. By next week, it will be lost in the glare of the rising Sun.

Wednesday: It is not winter yet. But Orion, thought of as a winter constellation, is just above the east-southeastern horizon at 5:00 a.m. By the actual winter, it will be visible in the evening sky. 

Thursday: Mizar is a well-known binary star in the constellation Ursa Major. You can find it at the bend in the Big Dipper handle, four fists above due northwest at 11:00 p.m. Its name is Arabic for waistband. Mizar has an optical double called Alcor, which is less than a pinky width away and can easily be seen with the naked eye. Optical doubles are stars that are close together in the sky but do not orbit a common center of mass as true binary stars. Not wanting to deceive sky gazers who call Alcor and Mizar a binary star, two stars that DO orbit a common center of mass, Mizar actually is a binary. It was the first binary star system discovered using a telescope. Mizar A and Mizar B are about 400 astronomical units apart from each other and about 80 light years from Earth. 400 astronomical units is about 10 times the distance between the Sun and Pluto.

Friday: Mars is one fist above the eastern horizon and one fist to the left of the Moon at midnight.

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.