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Harvest Moon Freaks Out Grownups, Not Kids: How To See It In NoVA

This is weird. The Harvest Moon on Sept. 24-25 will look a lot bigger than most full moons — but not to kids in NoVA and DC.

WASHINGTON, DC — Fall officially begins this Saturday and the Harvest Moon follows a couple of days later, resurrecting one of the great lunar debates: Why is the Harvest Moon so mind-blowingly big? It’s not. It’s one of those things your mind talked you into believing. It’s all in your head.

And your kids have an edge on you in this respect. They gaze at the moon over the horizon and see it as it is: The bright, orange Harvest Moon isn’t any bigger than any other moon, and they’ll remain unimpressed by the lunar hoopla.

We'll have to keep an eye on the forecast to see if northern Virginians can see the full moon in all its glory Monday night. Right now, the National Weather Service forecast calls for cloudy skies and a 40 percent chance of rain.

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RELATED: Fall Foliage Map 2018: When Autumn Leaves Peak In Virginia

Freaky, huh? When context is misleading, as it is with the Harvest Moon illusion, adults see the world less accurately than they did as children, according to researchers in the U.K. studying the Ebbinghaus illusion, the optical illusion of relative size perception.

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Among kids younger than 7, what’s around them doesn’t alter what they’re seeing right in front them. They’re still living in a what-you-see-is-what-you-get world.

The visual-attention system adds the context to determine the size of an object or thing. When things are far away, they’re usually surrounded by other things that look small, and things that are both small and close are surrounded by bigger objects.

But even if their eyes are telling them two objects are the same size, adults quickly recalibrate when they’re asked to reach for them, according to research suggesting there are two separate pathways for vision in the brain. One is used for identifying objects, the other for action.

Here’s a bit more to help you understand:

That fascination aside, the truth about Monday’s Harvest Moon is that while it will look like an oversized orange beach ball as it rises, it will actually be a bit smaller than the average full moon. The Ebbinghaus illusion accounts for how big the Harvest Moon looks, but what makes it appear orange?

It’s all about timing. The sunset and moonrise occur in almost perfect synchronicity. And the moon is the same color it’s always been. But both the moon and sun look redder when they’re by the horizon, and we see them on Earth through the maximum thickness of atmosphere, which absorbs the blue right and transmits red light. That’s where the orange comes from.

The first full moon after the autumn equinox is always referred to as the Harvest Moon, regardless of whether it falls in September or October. The September full moon is also known as the Full Corn Moon, so named by early Native Americans because it marked the time when corn was ready for harvest.

The Harvest Moon will rise at 7:13 p.m. ET on Monday, Sept. 24. It turns full at 10:52 p.m.

By Beth Dalbey, Patch National Staff

(Photo by Matt Cardy/Getty Images

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