I hope you had clear skies this past week and were able to see some Perseid meteors. I observed from very dark skies at Voyageurs National Park in northern Minnesota. There, the park staff and I shared telescopic views of Saturn, Jupiter and other cosmic wonders with some 70 vacationers as we watched meteors fly by till after midnight.
I often bring along a green laser to public events like these to highlight particular stars and constellations. At one point, I beamed in on the star Altair, and at that very instant a bright fireball streaked down the Milky Way from the spot. We all gasped at the sight — as if the laser had dislodged a star from the heavens — and then shared a good laugh at the coincidence.
Later, I set up a folding chair on a boat dock and quietly watched and photographed the shower until 3 a.m. I won't say I didn't occasionally doze off as the camera clicked away. All told, I counted about 35 meteors that night. The best was a brilliant, short-trailed fireball in Perseus that went off like a firecracker and left a bright train lasting 10 seconds.
The following night, August 12-13, was clear again with more Perseids. While hunting for comets before dawn with my telescope I casually spied another dozen. Most meteor showers originate from debris spread by material boiled off comets by the sun, so it seemed appropriate to give them their due during the Perseid peak.
To my surprise, I wasn't able to see a comet called 4P/Faye when it should have been visible. Later that morning, I learned that the coordinates were off. I downloaded new data and plotted its correct path. Like many of you, I rarely get up at 3 a..m. for stargazing unless there's something I really want to see. As it turned out, the next night, August 13-14, was also beautifully clear. Somewhat grudgingly I set the alarm to 3:15 to make a second foray for Comet Faye.
I not only saw the comet but something rather incredible. While the Perseids are active through the third week of August, the number of meteors visible normally drops off quickly after the peak. By the morning of the 14th the shower should have declined to about one-quarter strength. But no.
As I set up the telescope and camera I noticed one meteor after another sputtering across the sky. Many were bright. In the space of 45 minutes I saw 41 Perseids, more than at any other time during the shower, pushing my total meteor count to 88. At the time, I suspected that the Earth had encountered an unexpected, dense filament of material shed by Comet Swift-Tuttle, the Perseids' "parent" comet.
The meteors just kept coming even as the sky turned blue with twilight. Such an unexpected and rewarding experience.
Other observers also saw the surprise outburst which occurred between 1 a.m. and 4 a.m. Central Daylight Time (August 14), with meteor counts peaking at a rate 2-3 times that normally seen at maximum (August 11-12). A report from the International Meteor Organization assigned the cause to an unknown filament of Comet Swift debris left in its path during a pass through the inner solar system many centuries ago.
Meteor stream specialists generally have a good idea where dense streams of particles (called filaments) lie in a comet's orbit and when they were deposited. They use that knowledge to predict potential future shower outbursts. But unexpected things have a habit of happening when it comes to comets. It's one of the reasons we love them.
One lesson I learned from that morning is to not treat the Perseid shower as a one-night event. It never has been, but I usually promote and focus my efforts on the peak night. Next time, I'll take a Lollapalooza approach and spend time watching over several nights . . . just in case. The nearly full moon will ding the show in 2022, but 2023 will bring another round of dark skies.
I also learned several other things while watching this year's Perseids. There are LOTS of satellites and airplanes plying the night sky from dusk until dawn. We all know this, but when you give yourself over to just "looking up" it's kind of astonishing how much human activity happens up there.
Some satellites are fast, others slow. It all depends on their height — faster ones orbit at lower altitude. I also spotted a few random meteors including a super-slow, faint sporadic that burned for 3 seconds as it headed toward Perseus. Patches of airglow streaked the sky. Literally glowing air, it forms when molecules in our atmosphere are broken apart by sunlight in the daytime and later recombine and emit light at night.
Light pollution often brightens passing clouds, making them easy to spot crossing the sky at night. But in true darkness, clouds are invisible except when they pass in front of the Milky Way and appear in dark silhouette. Or when you happen to notice familiar stars suddenly "missing," only to see them return to view after the cloud has passed.
I enjoyed watching the fresh crop of winter stars rising in the east slowly "push" the summer bunch off to the west. With the fresh breeze, shirtsleeve temperatures, no bugs and a big sky overhead, a single thought stirred in my brain: I wanted to live forever.
"Astro" Bob King is a freelance writer for the Duluth News Tribune. Read more of his work at duluthnewstribune.com/astrobob.