Iowans will get front-row seat to longest lunar eclipse in 100 years

IOWA CITY — Although the retreat from daylight saving time might have worn off by Nov. 19, anyone still riding that extra hour into predawn wakefulness might get to see this month’s beaver moon turn blood red when North American gets a front-row seat for the century’s longest lunar eclipse.

Iowans willing to drag themselves from bed for the partial lunar eclipse — expected to last three hours, 28 minutes and 23 seconds, according to NASA — will start seeing the moon pass through Earth’s shadows after 1 a.m., reaching a maximum eclipse about 3 a.m., according to University of Iowa physics and astronomy Associate Professor Jasper Halekas.

“It should be very visible in Iowa,” he said. “Basically all over North America is maximum visibility.”

Of course, celestial viewing requires clear — or at least somewhat clear — skies. But should weather cooperate, the partial lunar eclipse over Eastern Iowa will start at 1:18 a.m., reach its peak — when the moon is closest to the center of Earth’s shadow — at 3:02 a.m., and end at 4:47 a.m.

Although this event isn’t officially categorized as a total lunar eclipse, the Earth’s shadow will block 97 percent of the sun’s light — meaning most of the moon will appear red in those predawn hours.

“There will be a little sliver of light around the edge of it, because it's not a 100-percent eclipse,” Halekas said, noting the rest “will probably end up looking a little bit reddish.”

Lunar eclipses are, essentially, the opposite of solar eclipses, Halekas said. Where solar eclipses occur when the moon moves between the Earth and the sun, blocking its light, a lunar eclipse occurs when the Earth moves between the sun and moon, blocking light the moon typically reflects.

Though the moon is in Earth’s shadow during lunar eclipses, some sunlight still seeps around and reaches the orbital body, according to NASA. But because it first passes through Earth’s atmosphere, most “blue light” filters out, making the moon seem red.

Lunar eclipses can occur only during full-moon phases. NASA reports Earth will experience 57 partial and 85 total lunar eclipses this century. The longest and shortest total lunar eclipses already occurred — in July 2018 and April 2015, respectively. The shortest partial eclipse won’t happen until Feb. 13, 2082, according to NASA.

The next total lunar eclipse is expected May 16, 2022, followed by another Nov. 8, 2022.

Lunar eclipses can be seen only in parts of the world where the moon is above the horizon. And the upcoming event is tailor-made for sky gazers in North America — with prime viewing across all 50 states, Canada and Mexico.

According to a map NASA produced, those living in South America, Western Europe and West Africa will see a portion of the eclipse at moon set. Australia and Asia will catch some of the eclipse at moon rise. And most of Africa and the Middle East will miss the whole thing.

Although scientists long have tracked orbital dynamics and have mapped out eclipses for hundreds of years, Halekas said they still can use eclipses to advance research — including their understanding of how the events affect the moon.

“It's kind of a unique physical situation where you go from having full light on part of the moon to having that light taken away and then having it come back,” he said. “And you actually can do some observations of what happens to the temperature of the surface as that happens that tell you some interesting things about the physical properties of the moon’s surface.”

As to whether Halekas plans to wake up early to catch this month’s unusually long blood moon, he hasn’t decided.

“I usually get up and go for my morning run at about 5 a.m.,” he said. “So it's only a couple hours early.”

Vanessa Miller covers higher education for The Gazette.

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