How to observe a ‘moon illusion’ when the strawberry full moon peaks tonight

By Taylor Nicioli | CNN

Despite its name, June’s full moon will not look like a strawberry. But the bright orb could still turn heads Friday night with an appearance that is bigger and more colorful than the average moon.

The full moon — which will reach the crest of its fullness at 9:08 p.m. ET Friday — comes one day after the summer solstice, the day of the year when the sun appears the highest in the sky for the Northern Hemisphere. Since a full moon is opposite the sun, this strawberry moon will shine lower in the sky than usual, according to NASA.

Because of this “lower than average path across the sky,” the full moon could have an “orange- or amber-colored appearance, for the same reason sunsets appear orange or reddish,” said Preston Dyches, a science communicator with NASA’s Jet Propulsion Laboratory in Pasadena, California, in an email.

Dyches said the effect is the result of the moon’s reflected light having to travel a longer distance throughout Earth’s atmosphere, scattering away most blue wavelengths (which are shorter than red wavelengths).

Native American tribes across North America gave the strawberry moon its name to mark the in-season ripeness of strawberries, according to The Old Farmer’s Almanac.

The moon’s low placement in the sky could also cause the orb to appear bigger than usual, according to NASA, due to an effect dubbed the moon illusion. Scientists don’t really know why this optical illusion happens, but it’s believed to be a combination of how our brain processes visual information and the moon’s size in comparison with smaller objects near the horizon, such as trees or the roofs of houses.

For optimal viewing, Dyches recommends looking when the moon is rising or setting to see the effects of the moon illusion. No equipment is needed to view a full moon, but a telescope or pair of binoculars could enhance its features, according to NASA’s Moon Viewing Guide.

“Whenever something beautiful about the natural world can be experienced from your doorstep, it’s worth a few minutes of your time,” Dyches said. “It’s rewarding to marvel at the sight of another giant world. … I like to gaze up and think of it as a place people will live and work someday.”

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