The Enterprise - White Salmon, Washington

What's in the sky: October

Star gazing column by Jim White

October 02, 2012

October, our first full month of Autumn, not only brings us scenic fall colors, but also dark skies at earlier hours, affording excellent opportunities to view the heavens above.

The month starts with a waning, although bright (95 percent illuminated) moon dominating the night sky. New moon follows on Oct. 15, with October's full moon coming on Oct. 29. Trick-or-Treaters will have another bright, waning moon to light the way on their evening adventures!

Speaking of Halloween -- few know that its roots are in astronomy. Oct. 31 is approximately a "cross quarter" day, half of the way between the beginning of autumn and the beginning of winter.

Another cross-quarter day, mentioned in my column last February, is Groundhog Day. Celts in the British Isles used these days to mark the beginnings of the seasons. While Groundhog Day was celebrated as a time when people had survived the winter, and looked forward to spring, Samhain, as Halloween was called, marked the beginning of tough times during hard winter months.

We've had a few months without bright planets in the evening sky, but that is coming to an end. Anyone who gets up early knows that we've had the bright planets Venus and Jupiter in our morning sky.

Jupiter is now rising in the evening. The solar system's largest planet rises about 10 p.m. early in the month, and is above the horizon at 8 p.m. at the end of October.

Jupiter's four largest moons -- called its Galilean moons as they were discovered by Galileo -- are visible with a good pair of binoculars. If you watch them from night to night, they change positions as they orbit Jupiter.

We'll also see winter constellations begin to appear in October. Jupiter will spend the month located between the "horns" of Taurus the bull. If you can find Jupiter, you can make out this famous constellation.

To the right of Jupiter will be the bull's face, with the reddish star Aldebaran looking like a blood-red eye of an angry bull. The rest of the bull's face is made up of a cluster of stars called the Hyades.

To Jupiter's left, as you look at the sky, you'll find the constellation Auriga, with its bright star Capella. Auriga appears as a rough circle of stars. Mythology sees it as a charioteer, and northwest Native Americans saw it as a circle of women, protecting their camas roots from a skunk. Those images prove difficult for me, but the circle is easy to make out.

The constellation Andromeda is high overhead in October. Our nearest neighbor galaxy, the Andromeda galaxy, is located here and is visible to the naked eye on dark nights, from locations away from artificial light. See if you can locate the faint smudge of its light; it took that light 2.3 million years to get here! It is easily visible in binoculars.

If you want an even greater challenge, look for the Triangulum galaxy, below and to the left of Andromeda when you face south. You'll need dark skies and binoculars for this one, although some can see it with the naked eye. Use the picture with this article for help.

Enjoy October skies!