The Ellensburg, WA sky for the week of October 16, 2021

Today: The bright star Antares is about a finger width below the much brighter Venus at 7:00 p.m. Both points of light are a half a fist held upright and at arm’s length above the southwestern horizon.

Sunday: Jupiter is nearly three fists above due south at 9:00 p.m. Saturn is a fist and a half to the lower right of Jupiter.

Monday: Rho Cassiopeiae is the most distant star that can be seen with the naked eye by most people. It is about 8,200 light years away. That means that the light that reaches your eyes from that star left over 8,000 years ago, before the beginning of time according to the Byzantine calendar. Rho Cassiopeiae is six fists above the northeastern horizon at 8:00 p.m., just above the zigzag line that marks the constellation Cassiopeia.

Tuesday: The October full moon is called the Full Hunter's Moon. The traditional Northern Hemisphere harvest time has ended so this is the month that many groups of people turned to hunting to build up their food supplies before winter. Also, since the Moon is full, it lights the sky the entire night, extending the time for night time activities.

Wednesday: The Orionid meteor shower consists of the Earth colliding with pieces of the remains of Halley's Comet's tail. This shower peaks after midnight for the next two nights. This is not a meteor shower that typically results in a meteor storm. There will be about 15-20 meteors per hour, many more meteors than are visible on a typical night but not the storm that some showers bring. The Moon is just past full, meaning it will be above the horizon during the peak time. The best time to observe will be near dawn. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Orion, the hunter. This point is about one fist above due east at midnight. You can follow this point throughout the night as it will remain one fist above the prominent reddish star Betelgeuse (pronounced Bet'-el-jews). The Orionid meteors are fast - up to 40 miles per second. If you fall asleep tonight, you can catch the tail end of the shower every night until early November. For more information, go to https://earthsky.org/?p=27937. 

Thursday: Mercury is a half a fist above the eastern horizon at 6:30 p.m.

Friday: Along with the not-so-subtle drug reference in their name, The Doobie Brothers could have made an astronomy reference in their song lyrics if they would have written: “Old Earth water, keep on rollin’, Mississippi moon won’t you keep on shining on me.” Astronomers now think that some of the water on Earth may be older than the Solar System. The chemical signature of the water indicates it came from a very cold source, just a few degrees above absolute zero. The early Solar System was much warmer than this meaning the water came from a source outside the Solar System. For more information about the old Earth water, go to http://goo.gl/QsEu5P.

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.