Halloween 2020 will have the first global blue moon since World War II

[thomdunn]

Originally published at: https://boingboing.net/2020/10/31/halloween-2020-will-have-the-first-global-blue-moon-since-world-war-ii.html

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[knoxblox]

I saw the run-up to the full deal yesterday in Tijuana. It was big and beautiful.

[scottslemmons]

There was a full moon on Halloween in 2001, but it was only visible in the Central and Pacific time zones.

So it just… skipped time zones? Full moon in the Central zone, waxing crescent in Mountain?

This is why editors are important.

[Mindysan33]

Here, too, driving home from the grocery store thursday night, it was big and beautiful…

[NukeML]

I could understand it being visible from pacific and mountain, or eastern and central. But skipping a time zone defies logic.

(Speaking for the continental USA. The world timezone map is quite bonkers)

[knoxblox]

Maybe it’s a positional thing, and the mountains were in the way?

[BakaNeko]

The flat earth theory explains It all.

[scottslemmons]

Giant angry cloudbank on a mission to keep Colorado from seeing full moons.

[Tommy_More]

The whole “skipping time zones” is preposterous, of course, but can someone explain why full moons don’t occur for all time zones on the same day? Is it that a true full moon might occur on consecutive days and not the same day in different time zones because the full moon is only truly full for about 24 hours?

I’m not asking the question well but just trying to understand why a full moon in NYC on 10/31 might not mean there’s a full moon in Auckland on Auckland’s 10/31.

Thanks

[scottslemmons]

Not an astronomer, and the answer is probably a lot more complicated than I suspect, but basically, I think it depends on the planet’s rotation and the fact that the moon’s phases are shifting constantly. Auckland might have a full moon on their Monday night, and NYC might have a full moon 12 hours later on their Monday night, but when the Earth rotates back around to Auckland’s Tuesday night, the moon would no longer be 100% full.

(Again, not an astronomer, and possibly a billion percent wrong…)

[NukeML]

You’re not far off. The moon’s orbit isn’t perfectly circular and so the further away it is in its orbit the longer the full moon will last. The moon hit apogee on 30 October, and so when you factor in the moon’s slower motion the whole earth got to see a full moon on 31 October.

When the moon has a full moon while at perigee it is moving faster and will whoosh through the full moon phase in under 24 hours.