Astro Bob: Skywatchers savor darkly beautiful eclipse
The forecast held true, with a very dark moon during totality. The likely culprit? Volcanic dust.
It's been a long time since I watched an entire lunar eclipse, but the experience made me eager to do it again. We had a few clouds, but the sky was otherwise gloriously clear and serene.
I shared the celestial syzygy with a rousing chorus of spring peepers from a nearby pond. As the moon progressed into Earth's shadow, they paddled across the water, sending ripples across the reflection of the diminishing moon.
During a lunar eclipse, the moon first enters the Earth's outer shadow or penumbra. Last night at 9:13 p.m. — 15 minutes before the start of partial eclipse — the gray-hued penumbra gently shaded the left (eastern) half of the moon. If you knew to look, it was obvious. Minutes later, the shadow was deep enough to "flatten" that side of the moon.
When about a third of the moon had entered the dark, inner shadow called the umbra, binoculars showed the faintest hint of orange along the moon's upper or northern limb. Meanwhile, back on Earth, the light had begun to wane. Shadows cast by the trees were still plain but weaker, and more stars speckled the sky.
At 10:38 p.m. CDT, just as the moon entered total eclipse, I happened to look up over my left shoulder and was startled to see dozens of Starlink satellites in a compact train proceeding in stately fashion to the east. The group, named Starlink G4-15 and launched on May 14, will be visible again Monday night, May 16, from the Upper Midwest and other locations.
I've included a map showing their path and times for Duluth, Minnesota, but to find out if and when they'll pass over your house, go to Heavens Above . Select your location by clicking on the blue "Change your observing location" link on the left side of the page, then return to the home page and click on the bold, blue "Get Predictions" link in the write-up at the top of the page. Once there, note the visibility time, then click on any satellite for a map showing their group path.
Now back to the eclipse. At totality's start, the yellow-rimmed, orange-red lunar disk was easy to see. But as the eclipse approached maximum (11:11 p.m. CDT), the moon really got faint. Its bottom edge, shaped like a smile, glowed dimly yellow, while the rest of the disk was so dark it appeared colorless at first glance. Looking more closely, I could make out a deep brownish-red hue.
The top or north end of the disk — closest to the center of Earth's umbra — was so faint I had to use averted vision to make out the full circle of the moon. What did you see? Please share your photos and impressions on my Facebook page .
Even through 6-inch and 10-inch telescopes, the moon appeared muddy and dim. The lunar seas Serenity and Tranquility, which together make the two googly eyes of the Man-in-the-Moon face, were spectacularly dark. Two black eyes! By chance, the area of the moon rich in dark seas happened to be passing closest to the center of the umbra, further darkening totality. Volcanic dusk from the powerful Tonga volcano blast likely contributed as well.
It was fascinating to watch the moon brighten and grow more colorful after mid-eclipse as it slowly worked its way across the the umbra before exiting at 11:54 p.m. CDT. Seeing the transition helped me picture Earth's shadow more clearly. I could picture the narrowing cone of darkness beginning from where I stood and reaching all the way to the moon. For a few moments, space felt truly three-dimensional.
That first sliver of sharp, white sunlight along the moon's edge made a dramatic contrast with the darkened disk and signaled the end of totality. I could have gone to bed. It was midnight after all. But the slow majesty of the event kept me watching. I had to see the parade to the end. Every band. Every float. So I stayed up, took a walk and checked in with friends as the moon escaped from its dark dream.
Funny how eclipses work. It's basically a shadow-exchange. When the moon enters the Earth's shadow, the ones we cast disappear. Once the moon leaves the shadow, they return, weakly at first, but with ever-increasing depth. By 1:30 a.m., the brilliance of the moon had been restored. The lights were back on. It was safe to go to bed.
"Astro" Bob King is a freelance writer for the Duluth News Tribune.