Zugunruhe, as any ornithologist could tell you, is a German word for “migratory restlessness.” At certain times of year birds feel anxiety, agitation, and a deep desire to move. Scientists still aren’t sure how it happens exactly. The restlessness just arrives like the autumn wind. Perhaps you, too, have known Zugunruhe recently.
Many migratory birds seem to respond to Zugunruhe by looking to the night sky. In the mid-1960s, a scientist named Stephen Emlen took two dozen indigo buntings who were showing signs of restlessness and moved them to outdoor cages that blocked the view of everything but the stars. Underfoot, he placed an inkpad and blotting paper to record the direction of the birds’ movement. He wondered if, with only celestial cues to guide them, the birds would hop in the direction of their annual fall migration. Most did, Emlen reported in 1967 in The Auk journal of ornithology. They did so even when he later moved them into a planetarium with the same view of the night sky but the stars set in the wrong magnetic directions. They did not, however, hop south as often on cloudy nights.
A 2018 article in the Proceedings of the Royal Society B by postdoctoral zoologist James Foster suggests indigo buntings are not the only ones in the animal kingdom who appreciate the night. Scientists have trained harbor seals to touch planetarium walls beneath the star Sirius for a reward, even after the images of Sirius and its nearby constellations were moved—a sign, scientists thought, that the seals may orient or navigate by specific star patterns.
In the insect world, dung beetles like a starry sky for hiding their dung balls. Beetles still find their way from the dung pile to their nearby buried treasure on moonless nights, but not so in the absence of starlight; scientists think the beetles must navigate by the brilliance of the Milky Way. Night-flying moths in the Noctua genus metamorphose and disperse by the stars. By tethering the moths to small posts and then noting the direction they tried to fly, scientists found that the moths may orient their flight toward the brightest part of the Milky Way.
And of course, we humans love a starry night. Long fall and winter nights tend to provide the best stargazing in Northern California. Warm autumn temperatures bring freedom from fog. Beloved winter constellations like Orion and star clusters like the Pleiades rise. The belt of the Milky Way sinks over headlands and hills. Meteor showers streak out of the north. People like photographer Marsha Kirschbaum feel the call of fog-free nights and take a nocturnal turn, heading for sparsely lit areas of the coast or East Bay hills.
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Kirschbaum, who shot the image on this issue’s cover, sees her adjustments to the rhythm of the stars as a way to orient toward the wider world. You don’t need a calendar to mark the passage of time when you look up at the sky. Constellations, meteors, and planets come and go in harmony with California’s changing weather, blooming and senescing plants, and migrating animals.
“There’s a perspective that it brings, where there are things greater than your everyday,” Kirschbaum told me. “It lets those everyday concerns float away. There’s just something about the cosmos that’s healing.”
Kirschbaum also shared her concern that our view of the night sky is increasingly threatened by light pollution and space junk. “We are losing it,” she said. Worse, she says, many people don’t seem to know what they’re losing. Otherwise, how could they accept such unnecessarily bright light or launch so many unregulated satellites? How could anyone who has ever really seen the Milky Way live life without worrying about damaging our ability to see it again?
Of course, pointing out the irreplaceable value of wild places rarely slows their destruction. The same economic and political ruts that allow private companies to launch thousands of satellites and obscure our view of the stars have bleached the coral reefs, paved the deserts, burned the rainforests, and mined the deep seafloor, just as they have displaced people, destroyed cultures, and threatened our relationship with facts and truth. From that perspective, what is a clear view of the night sky but one more nerve end to cauterize?
But one of the wonders of the universe is that the light from those stars takes so long to reach us that we see, quite literally, the past. The red light of Betelgeuse shows us that star as it was 650 years ago; the blue light of Rigel travels 860 years to land on our eyes and telescopes. Fall and winter is the best time of year to see the constellation Cassiopeia, which includes one of the farthest-away stars visible to the human eye. When we gaze up at the giant star Rho Cassiopeiae, we see light that left it 3,443 years ago. That was right around the time the Greeks on our planet named its constellation after a queen who angered the gods with myopic vanity.
Zugunruhe may call all of us this fall. If you’re feeling restless, remember the birds, who in their agitation look up. Find, as they might, a place where the stars shine bright; look up at the gleam of the past that illuminates our present darkness. Remember then that the birds don’t look only to admire. The beauty that surrounds us heals, but it is still a step on the way to flight, to charting a future where the light still shines.
What to See
Fall and winter offer opportunities to see many of the most beloved celestial sights.
»In September, summer constellations make their last stand. The “Summer Triangle,” formed by the bright stars Deneb, Altair, and Vega, appears high in the sky an hour after sunset, with Deneb and its constellation Cygnus (the Swan) almost straight overhead. Look, too, this year for Jupiter and Saturn, closer together than they’ve been in centuries: two bright dots about 30 degrees above the horizon in the southern sky.
»In October, the faint band of the setting Milky Way core appears in the southwest as soon as it’s dark. On a moonless, clear night, you might even be able to follow it back up from the southern horizon through the also-sinking bird constellations Cygnus and Aquila. On October 21-22, the Orionid meteor shower shoots out of the Orion constellation late at night and into the early morning.
»In November, Orion begins rising earlier in the east around 9 p.m. Look for the contrasting colors of Betelgeuse, the red supergiant star that forms Orion’s left shoulder, and Rigel, the blue supergiant that forms his right foot. In the middle you’ll find his belt, and farther down a bit hangs another three-dot pattern—his sword. With binoculars, the middle “star” in the sword becomes more apparent as the fuzzy Orion Nebula, a massive cloud of dust and new stars known as a stellar nursery.
»The Geminid meteor shower arrives December 13-14 at the edge of winter, coinciding with a new moon and perfect dark skies to allow views of shooting stars. If it’s clear, look for the constellation Gemini rising in the east a few hours after sunset and proceeding from east to west across the sky all night.
Where to Go
»The excellent lightpollutionmap.info shows a high-resolution and navigable map of worldwide light pollution. Point Reyes National Seashore, Henry Coe State Park, and the Clear Lake area offer the darkest skies within an hour of the urban Bay Area (unless you’ve got a boat and can go 20 miles offshore after dark).
»Chabot Space and Science Center has been closed to live events since March, but its astronomers have taken their star knowledge online. They offer virtual telescope viewings and monthly Northern California sky tours on Facebook Live. Find out more at chabotspace.org.
»There are numerous online planetariums with live sky views. Stellarium-web.org shows stars, planets, constellations, and the Milky Way at your location, in an easy-to-navigate window.
»The Astropheric app (astropheric.com) offers detailed weather forecasts featuring the specific details that matter to stargazers, including cloud cover, humidity, and sunset and sunrise times.