The early darkening night time skies of October in the Chicago area are ripe with planetary bodies and constellations that can be seen with the bare eye. According the the Adler Planetarium Sky Watching guide, four of our galaxy’s planetary bodies can be seen this time of year. The crisp clear early fall nights are the perfect time to head out to the outlying rural neighborhoods of Southern Chicagoland for an evening of sky watching.
Your evening can begin about half an hour after sunset with the appearance of normally hard-to-see Mercury shining very low in the southwest sky. If you let your eyes wander directly north of this little planet you will find the constellation Ophiuchus, or the snake holder, and it’s sister constellation Serpens, the snake. Directly north of this you can locate the constellation Bootes, or the Herdsman.
Roughly an hour after viewing Mercury, in the same general location Mars will sweep into view in the southwest sky, shining brilliantly and often mistaken for a nearby celestial body, Antares. Both bodies are used as points in the fall constellation Scorpius, or the scorpion. If you look directly left of Mars, you can locate the constellation Sagittarius, the archer, and to the north of Sagittarius are Scutum, the shield and Aquila, the eagle.
After viewing these stunning autumn constellation, try to locate the ever bright planet Jupiter in the south southeast portion of the sky. Jupiter is only a few degrees from the center of the Taurus constellations bull horns. To the east of Jupiter, you can see the bright shining celestial body Betelgeuse in the top corner of Orion the hunter, which is barely poking its way into the sky around this time of evening.
Since the next visible planet, Venus, does not migrate into the night time sky until the very early hours of darkest morning, you can spend a great deal of time looking for the other major visible constellations made brilliant in the autumn sky.
Directly aligned next to the Moon, you can see the constellation Pisces, the fish. North of the moon the constellation Aries, the ram, can be found, as well as the small constellation Triangulum, which looks like a triangle and is one of the smallest constellations found in the Northern Hemisphere. Continue north and you will come across Perseus, the son of Zeus. To the west of the Moon, you can locate the constellation Pegasus, the winged horse, and its sister constellation Andromeda, the chained maiden of folklore who was rescued by Pegasus.
Traveling north of Pegasus are the constellations Cassiopeia and Cepheus, the Ethiopian Queen and King.
As the nighttime sky progresses and Venus makes its appearance in the low southeast of the sky at the tail end of the constellation Virgo, the virgin. In the sky line between Venus and Jupiter, you can easily locate three more astrological constellations, Leo the lion, Cancer the crab, and Gemini the twins, in order from east to west.
You can finish your evening of sky watching by finding the ever present Ursa Major, the big dipper or great bear, in the northeastern center of the night time sky in perfect stance.