October brings not only cooler temperatures, but also clear and hopefully smoke-free skies. If you find yourself outside under the planets and stars, here are a few things you might see up there.
Low in the southwest, Venus gleams brightly in the twilight sky just after sunset. If you cannot spot it, maybe you cannot see low enough towards the horizon, so try another location. Venus will be our evening star in the west until early winter.
Turn towards the south or southeast to see Jupiter higher above the horizon. Notice that neither is twinkling like the stars, a clue that they are planets. To the right of Jupiter, a much-dimmer Saturn is easy to spot when it gets almost dark. These are the three naked-eye planets on display this month, and they make an almost straight line across the southern sky. What you are seeing is the plane of our solar system that all the planets and their major moons travel through as they orbit our sun.
Our moon will dance with each of those planets for a night this month. Look for it just above Venus on Oct. 9. Then on Oct. 14, it will pass below Saturn and the next night watch for it beneath Jupiter.
Into the depths
The true “stars” of the night sky are the stars, the far-distant beacons shining from the depths of the cosmos. Look up just a little west of overhead for the Summer Triangle, three bright stars in a large open triangle. The brightest and the most-western of the three is Vega, the vulture star. It shines 50 times as bright as our sun and is about 25 light years away, which means the light you are seeing left the star 25 years ago. Vega will be the North Star about 12,000 years from now due to a slow wobble of the earth. If you can wait that long, it will be much brighter and easier to find than our current one.
The southernmost of the three stars is Altair, the eye of the Eagle. It is one of the closest stars we can see early in the evening in October at 17 light years away. Even so, it would take one of Elon Musk’s rocket ships hundreds of thousands of years to cover the distance.
To the north in the triangle lies Deneb, the tail of the hen. It is one of the brightest and most-distant stars we can see. Its light, when it hits your eye, has been traveling since Biblical times across a vast void of empty space. Make sure you bring some snacks and a few books to read for the journey.
Later in the month
Look low in the south beneath Jupiter for the star Fomalhaut. If you can pronounce its name without Googling it, you deserve a gold star. The strange name means the mouth of the fish, which is appropriate since it lies in the constellation of the southern fish. It is a close neighbor of ours, cosmically speaking, and is probably forming planets around it right now.
Later in the month, if you can see low into the east, you might spot the Pleiades star cluster, a little gem that hangs out with us all winter.
Towards the end of the month, look for the planet Mercury in the early morning twilight right above where the sun will rise. Predawn is also a great time to see the unearthly Zodiacal Light, a glowing pillar of light rising upwards from the eastern horizon. Be sure you are out somewhere away from distracting lights. It is caused by sunlight reflecting off of particles of dust in our solar system. If you are up that early, the bright stars of winter will be showing off what is to come in a couple of months. I will talk about all that later.
