In the October sky, plenty to see: a queen, a sea monster, a galaxy
Now that the evenings are turning chilly and dark, the first bright stars of winter are already climbing up the eastern sky. You can see some of them even through the skyglow over Greater Boston.
Go out after dark, face northeast, and look fairly high -- at least halfway from horizontal to straight up. You're now looking toward the landmark cold-weather constellation Cassiopeia. It's a flattened W-shape made of five stars. The right-hand side of the W (the brighter side) is tilted up.
Cassiopeia, in ancient Greek mythology, was a queen of Ethiopia mourning for her daughter Andromeda, who was chained to a rock by the ocean as a sacrifice to a sea monster. A flattened W doesn't make much of a queen, but for most of human history the night sky was dark enough to be studded with thousands of stars -- enough to make more imaginative patterns than we can see through the skyglow over Eastern Massachusetts. Several fainter stars can be added to the four in the W to make a surprisingly evocative profile of a woman bending with head bowed in sorrow. And indeed, the correct stars of this figure bear ancient names for ''breast" and ''knee."
Alternatively, the W itself is sometimes called Cassiopeia's Chair. It looks uncomfortable.
Below Cassiopeia and a bit to the right is a scattering of stars forming the constellation Perseus. In the myth, Perseus was a rescuer arriving on a winged horse to save Andromeda -- who is represented by a big scattering of stars to Cassiopeia's right (not shown here). Perseus is reaching to the upper right to grab her foot. The sea monster in the story, Cetus, is another large constellation looming low in the east-southeast.
Lower and to the left of Perseus shines Capella, the Goat Star, one of the brightest in the sky. If the light pollution in your area is too bright for anything else to show through, at least Capella ought to be visible. If it's too low behind buildings or trees, wait another hour or two for it to rise higher.
By late evening another, even brighter light will be shining in the east, far to the right of Capella and just about as high. This is the planet Mars. It's currently swinging close by Earth and brightening every week. Mars will be nearest and brightest at the end of October -- nearer than it has been since 2003 and nearer than will be until 2018. Although Mars is often called the Red Planet, it actually shines fiery yellow.
A good view of the stars in a dark, unpolluted sky has become, for many people, one of the best reasons to get away to the wilderness. If you're far from overlighted towns on October evenings, you'll see a grand sight towering up in the northeast behind Capella, Perseus, and Cassiopeia: the autumn Milky Way. Our home galaxy, viewed from our position inside it, appears as a wide, irregular, richly detailed band of light that currently extends straight up in the northeast, passes overhead, and continues down to the southwest horizon. This is the combined light of billions of distant stars, mottled with dark patches of interstellar dust silhouetted against them in the foreground.
The Milky Way was an everyday sight for your great-grandparents. When they went out to milk the cows before the first light of dawn, their view of our galaxy was as clear as astronauts view it from outer space.
We know vastly more about the universe now than your great-grandparents could have guessed -- and by ''we" I mean anyone who checks out a couple of good astronomy books from the library. But most people see so much less. The great trend in astronomy throughout my life has been ever-better telescopes and technology in an ever-poorer environment. A microcosm, perhaps, of what's happening all over.
Alan M. MacRobert is a senior editor of Sky & Telescope and Night Sky magazines in Cambridge (SkyandTelescope.com, NightSkyMag.com). His Star Watch column appears the first Saturday of every month. 
