Starwatch: October skies light up with meteors, hunter’s moon
October’s dark and often clear skies are perfect for enjoying the fall constellations. Some of them are fairly dim, but if you like a challenge, grab a star chart and go outside soon after nightfall.
One good target is Pegasus, the winged horse, easily recognizable by its sizable Great Square high in the southeast. Close by is Andromeda, a double string of stars extending from the Great Square’s northeast corner. Its most famous feature is a fuzzy patch of light: the Andromeda Galaxy.
At 2.5 million light-years away, Andromeda is our Milky Way’s nearest large neighbor and the most distant object visible to the naked eye.
Close above the southern horizon shines Fomalhaut, the only remarkable feature of Piscis Austrinus, the southern fish. Fomalhaut’s name derives from the Arabic for “mouth of the fish.”
A fixture of science fiction, Fomalhaut is about 25 light-years away, twice as massive as the sun, and 16 times brighter. It also has a wide disk of dust and debris. It’s known as “the loneliest star” due to the expanse of nearly empty sky around it.
But now, Fomalhaut has a companion in Mars, the bright light just off to the northwest.
Mars spends October in chevron-shaped Capricornus, the sea goat. Watch the stars of Capricornus stream past Mars from night to night as Earth’s orbital motion sweeps them westward. We’re actually sweeping Mars westward, too, but much more slowly because the red planet’s own orbital motion helps it resist being left behind.
Meanwhile, above and east of Mars, scraggly Aquarius, the water bearer, pours down its water from the Y-shaped Water Jar. Next to the Water Jar and right below the Great Square, look for the ring-shaped Circlet of Pisces.
The Draconid meteor shower peaks in the evenings of Oct. 7-9. Usually, we get just a handful of these slow-moving meteors per hour, but occasionally they put on a real show.
If you decide to take a chance on it, go out right after nightfall, lie back in a lawn chair and look to the northwest. Any Draconids you see will radiate from a spot high in the northwest, in the constellation Draco, the dragon.
On Oct. 10, see if you can spot a young moon close to the west-southwest horizon right after sunset. The next night, a three-day-old crescent pairs up with Jupiter. Look an hour after sunset but no later, or Jupiter may have set.
October’s full hunter’s moon arrives on the morning of the 24th, but sets before reaching complete fullness. To see it at its roundest, try to get outside about 45 minutes before sunrise that morning, or watch it rise that evening.
University of Minnesota offers public viewings of the night sky at the Marshall W. Alworth Planetarium on its Duluth campus. Visit d.umn.edu/planet for more information and viewing schedules.