The Ellensburg, WA sky for the week of October 24, 2020

Saturday:  Halloween is next weekend so make sure you load up on peanut clusters, almond clusters, and open star clusters this week. That last one will be easy (and cheap… actually free) because two of the most prominent open star clusters in the sky are easily visible in the autumn sky. The sideways V-shaped Hyades Cluster is two fists held upright and at arm’s length above due east at 10:00 p.m. containing over 300 stars; the Hyades cluster is about 150 light years away and 625 million years old. The Pleiades Cluster, a little more than three fists above due east, is larger at over 1000 stars and younger. Compared to our 5 billion year old Sun, the 100 million year age of the Pleiades is infant-like. 

Sunday: Last year, the Hubble Space Telescope got the first close-up view of a comet from another star system. Comet 2I/Borisov was discovered by amateur astronomer Gennady on August 30, 2019 as the second interstellar object ever confirmed. 2I is the new official designator for the second interstellar object. Astronomers know it is from another star system because it is going way too fast, 110,000 miles per hour, to be gravitationally bound to the Sun. Read and watch more about the discovery at http://tiny.cc/mhh0tz. 

Monday: Venus is two and a half fists above the east-southeastern horizon at 7:00 a.m.

Tuesday: What time is tea time? Certainly not during an autumn evening. The constellation Sagittarius the archer, with its signature teapot shape, is sinking into the south-southwestern horizon by 7:00 p.m. The handle is on top and the spout is touching the horizon ready to pour that last cup of tea. Saturn is riding the teapot, about one and a half fists above the south-southwest horizon.

Wednesday: Mars starts the evening one fist to the left of the Moon, low in the eastern sky right after sunset. By midnight, the Moon has moved a little closer to Mars. Both are more than four fists above the southern horizon.  By 5:00 a.m., Mars and the Moon are a half a fist apart, low in the western sky.

Thursday: Bright Jupiter is two fists above the south-southwestern horizon at 7:00 p.m. Saturn is a half a fist to the upper left of Jupiter. Pluto, not visible even with a small telescope, is between the two giant planets.

Friday: Uranus is in opposition tonight. That doesn’t mean it refuses to work with the other political party. It means that Uranus is on the opposite side of the Earth as the Sun is so it is highest in the sky during the darkest part of the night. Also, it is visible with binoculars for the entire night. Go outside at 9:00 p.m. and find the Moon. Put the Moon in the lower right portion of your binoculars. Uranus will be in or just outside the upper left portion of your field of view. Follow the object throughout the night. By 5:00 a.m., Uranus will be to the upper right of the Moon. Try to find Uranus for the next few nights. You’ll know you have the right object if it moves a little bit to the right each night compared to the background stars.

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.