What to know about Friday’s partial lunar eclipse
The inconstant moon’s full face will be eclipsed this week, glowing bright amber or burnt umber, joined by the Seven Sisters.
Seeing it — the longest partial lunar eclipse of the century, so nearly total that only purists will pooh-pooh it — will require the always dicey Connecticut weather to cooperate.
But it will also require a certain amount of effort on any skywatcher’s part.
The eclipse will begin in the wee small hours of the morning Friday at 2:19 a.m. and peak at 4:04 a.m. when the moon will be high in the western sky. It will end at 5:47 a.m., near sunrise.
“You either have to stay up real late Thursday night or get up real early on Friday morning,’’ said Monty Robson, director of the John McCarthy Observatory in New Milford.
Robson said, if the clouds don’t gather, he’ll be up.
“It’s always interesting,’’ he said.
So will Cliff Wattley, of Ridgefield, who helps organize the astronomy nights at New Pond Farm Education Center in Redding.
“Maybe I’ll sleep over at my grandkids house and get them up to see it,” he said.
Bill Cloutier, of New Milford, one of the directors of the McCarthy Observatory, said he’s thinking of where he can photograph the eclipse the best.
“There’s always this mystique about the moon,” said Cloutier. “Each eclipse is a little bit different.”
A lunar eclipse occurs when the sun, earth and moon line up so that the earth’s shadow blocks the sun’s light from illuminating the full moon in its usual pale gold. They’re in syzygy, a word beloved by crossworders.
A total lunar eclipse is when the earth’s shadow covers the moon’s face completely. It’s a blood moon because the sun’s light flowing around the earth gets filtered through the earth’s atmosphere. That filtered light can color the moon red. Or copper. Or salmon.
Diana Hannikainen, observing editor of Sky & Telescope Magazine, said if you could stand on the moon’s surface and look at the earth during a lunar eclipse, you’d see it ringed in a corona of red light.
“It would be amazing to see,” she said.
Friday’s eclipse will be 97 percent total — enough to make the moon, that harsh mistress, red-faced.
“It will be about as close to total as it can be without being total,” said Geoff Chester, spokesman for the U.S. Naval Observatory in Washington DC.
And unlike solar eclipses — which are short-lived and travel a narrow path — lunar eclipses cast a wide shadow. This one’s near-totality will be on view in eastern Russia, Japan, eastern Australia and North America.
It will be a long eclipse because the moon’s orbit is nearly at apogee — its farthest distance from the earth — at 252,450 miles. Because it’s farther away, the earth’s shadow covers it longer, said Chester, of the Naval Observatory.
The color the moon during a lunar eclipse depends on how much dust and contamination is in the atmosphere. If there’s been a volcanic eruption and lots of high-atmosphere soot, the moon can be very dark. If not, it can be almost amber-colored.
“The more schmutz is up there, the darker the color,” Chester said.
The moon, while inconstant, is ever-fascinating.
Astronomers now believe the moon was created when two early planets collided 4.4 billion years ago.
Cloutier said that by studying the moon, we can learn about what the earth was like since that big crash.
“It’s a time capsule,” he said.
And humans have been watching eclipses for a very long time. Chester said the ancient Greeks, seeing that the earth’s shadow fit over the moon in a circle, theorized the earth was circular-shaped as well.
And unlike some of nature’s phenomena, astronomers can calculate when eclipses — solar and lunar — will occur far into the future. It’s the clockwork of the heavens.
“They happen,” Chester said.
So if you miss this one — if it’s overcast, if you decide to sleep in — don’t despair. There will be another lunar eclipse — a truly total one — visible to North and South America on May 15, 2022. It will also be more accessible, beginning at around 9:30 p.m. and reaching totality around 11:30 p.m.
However, Friday night’s eclipse will have a brilliant partner. When it’s fully glowing red at 4 a.m., it will close by the Pleiades, aka the Seven Sisters — the most beautiful star cluster in the night sky.
“Think of what a picture it will make,” Hannikainen said.