When my daughters were little girls, cool summer evenings sent them into a tizzy.
“Can we have a campfire tonight?” they’d ask.
They had learned on their first trip to the hayfield as toddlers that nature shared many secrets under a dark summer sky.
My wife and I enjoyed campfires as much as the girls did, so we’d haul firewood, a blanket, and supplies to a high spot a few hundred yards beyond the garage. We’d roast marshmallows and then relax on our backs as darkness fell.
One by one, stars popped onto the night sky.
On a good night, a great horned owl might hoot in the distance, or an eastern screech-owl might whistle from the nearby edge of the woods. The screech-owl’s voice is anything but a screech; it’s either a monotone trill or an eerie quavering whistle. Each song is distinctive and recognizable.
Star watching
As stars illuminated the sky, fireflies flashed Morse code-like dots and dashes of bioluminescence. Fireflies or lightning bugs, as they are sometimes called, are actually beetles, not flies or bugs, and their nightly light shows are actually mating rituals.
Species of fireflies can be identified by their specific flash patterns. Like songs enable birds to recognize members of their own species, unique visual flash patterns prevent male fireflies of one species from wasting time and energy trying to mate with females of the wrong species.
For a particular species, the flash system works something like this. At sunset, males crawl out of the grass and begin to fly. Every seven seconds each male emits a half-second flash. The flashes are not synchronized, so a casual glance suggests these insects are flashing at random. Follow one individual, however, and the pattern emerges.
Making contact
Eventually, a female recognizes the male flash pattern for her species. Precisely three seconds after each male flash, the female replies with a half-second flash. When the male sees the appropriate flash coming at the appropriate time interval, he flies closer to investigate.
The male continues to flash at seven-second intervals, and the female responds in kind every three seconds. They may repeat this exchange ten times or more. Eventually, the male flies down to the female, who is hidden in the grass, and the pair mate.
After the sky turns completely black, human eyes acclimate to the darkness. Though roughly 3,000 stars can be seen with the naked eye on a clear summer night, it’s best to avoid being overwhelmed by concentrating on just a few prominent stars.
In June, for example, the Summer Triangle appears in the eastern sky shortly after dark. It swings overhead as time passes and sits high in the west at dawn.
Find the Summer Triangle by looking to the east around 10 p.m. The highest, brightest star is Vega. Down and to the left is Deneb, and far down and to the right is Altair.
The Summer Triangle is not a constellation, but these three bright stars are part of three separate constellations — Lyra the Harp, Cygnus the Swan, and Aquila the Eagle, respectively.
After finding the Summer Triangle, follow it all summer long as it first moves higher in the east and then nearly overhead later in the summer.
Look for planets
Three planets are also just beginning to put on a show for the summer. Look for Mars in the southeast sky shortly after 9 p.m. Its reddish glow is distinctive. Saturn trails Mars, and together they move westward across the sky all night long.
And after you find Mars, look across the sky to the southwest. The brightest object in the sky, other than the moon, is Jupiter. With binoculars, a few of Jupiter’s moons are sometimes visible.
Making memories
Every family can make summer memories by listening for owls, observing fireflies, and identifying heavenly bodies. And if buildings or trees obstruct your view of the night sky, watch for notices of star parties at local parks and nature centers.
For more details about the night sky, visit www.earthsky.org, and www.skyandtelescope.com.
