It’s a full moon Saturday, but Friday’s version will be the star over Philly

Be it the Paschal, Pink, or When-the-Ducks-Come Home Moon, Saturday’s full moon will be a momentous one for the world’s religious calendars and for lunar connoisseurs.

And what’s more, you don’t have to wait for it. In fact, it’s better not to. The skies are likely to be cloud-congested Saturday night and, besides, the moon won’t exactly be “full.”

It will be beaming almost the same amount of light on Friday night, and at times when more admirers are likely to be awake. On Friday, it rises at 6:34 p.m. — a full hour and 16 minutes before it does Saturday — and should be beaming brightly by 9 p.m. or so.

A moon at this degree of fullness won’t be visible so early until October.

Given all the urban light interference around here, the moon often is the star of the night sky, the backlighting for those intricate tree shadows and animating the blooms and blossoms with that subtle, reflected silvery light.

» READ MORE: Here are some darker-sky options in the Philly region.

Subject to change, of course, the forecast suggests that the best viewing window would be before midnight Friday, said Michael Silva, a meteorologist at the National Weather Service Office in Mount Holly.

Technically, the moon won’t be full, but in the court of common sense, it would matter only to a true celestial nitpicker.

The moon is restlessly waxing and waning. It is full, that is at 100% illumination, only for an existential instant. That moment will be an anticlimax this time around since it occurs at 2:55 p.m. Saturday.

Late Friday night, according to NASA, it will be at 99.4% illumination and waxing, on Saturday night, 99.8% and waning.

The behaviors of the sun and moon are inextricably related. Moonrise and moonset closely parallel sunrise and sunset, since the instant of fullness occurs when the moon is directly opposite the sun. Saturday’s full moon will rise at 7:50 p.m.

Over the next few months, moonlight gradually loses more air time. The rises come later, the periods of darkness shorter, and the higher the sun rises during the day, the lower the moon rises at night, says Harry J. Augensen, director of the observatory at Widener University, where he is a professor emeritus.

“In the summer full moons ride low in the sky and are up only about nine to 10 hours, while in winter full moons ride high in the sky and are up 14 to 15 hours, the opposite of what applies for the sun,” he said.

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The moon is called “Super” when it makes its closest approaches to Earth. The most recent one was in December, when it was a mere 221,702 miles away, said Michael Brown, physics professor at Swarthmore College. Last May it was at its farthest point, 252,595 miles.

» READ MORE: Just what is a 'Super Moon'?

The closer it is, the larger it appears, and the difference between what was visible to the naked eye in May vs. December is similar to the difference between a nickel and a quarter, he said. This one, at 242,247 miles away, or about $40,000 worth of highway-driving gas at today’s prices, will definitely be worth more than a nickel.

The next Super Moon will be the “Strawberry Moon” of June 14, appropriately during the strawberry season.

The April full moon has quite a resumé. Traditionally it is known as the “Pink Moon.” That’s not a hallucinatory reference: According to the Farmers Almanac it takes its name from the “ground phlox,” a pinkish mountain wildflower that appears this time of year in the Eastern United States.

Other colorful names attributed to Indigenous peoples include Moon When the Ducks Come Back, Moon When the Geese Lay Eggs, and Frog Moon.

This also is the Paschal, the Latinized variant of Passover, Moon. Passover begins at sundown Friday, which is Good Friday in the Christian calendar. Easter always occurs on the first Sunday after the first full moon of spring, and in most years the two feasts overlap.

For Hindus, this full moon also coincides with Hanuman Jayanti, the celebration of the birth of Lord Hanuman, notes NASA’s Gordon Johnston, and for Buddhists, Bak Pooya, commemorating when the Buddha brokered a peace among Sri Lankan chiefs.

As the moon is getting ready to call it a night, it will be yielding the stage to the planets. Saturn, Venus, Mars, and Jupiter will be lining up on the eastern horizon in the predawn sky around daybreak during the weekend, said Augensen.

And during the next full moon, May 15, it will yield the sky to whatever planets and stars one can discern.

» READ MORE: A lunar eclipse occurred in November.

A total eclipse will get underway that night and continue into the morning hours of the 16th.