Science

Saturday! Up in the sky! It's Supermoon!

Posted May 4, 2012

— The biggest and brightest full moon of the year arrives Saturday night as our celestial neighbor passes closer to Earth than usual.

But don't expect any "must-have-been-a-full-moon" spike in crime or crazy behavior. That's just folklore.

Saturday's event is a "supermoon," the closest and therefore the biggest and brightest full moon of the year. At 11:34 p.m., the moon will be about 221,802 miles from Earth. That's about 15,300 miles closer than average.

That proximity will make the moon appear about 14 percent bigger than it would if the moon were at its farthest distance, said Geoff Chester of the U.S. Naval Observatory. The difference in appearance is so small that "you'd be very hard-pressed to detect that with the unaided eye," he said.

The moon's distance from Earth varies because it follows an orbit that is more of an oval than a perfect circle.

Like any full moon, the supermoon will look bigger when it's on or near the horizon rather than higher in the sky, thanks to an optical illusion, Chester noted. The full moon appears on the horizon at sunset. On the East coast, for example, that will be a bit before 8 p.m. Saturday.

"Look off to the east where the moon always rises, and look for the moon rising up over the trees and the houses," advised Tony Rice, a NASA solar system ambassador who works in the Triangle. 

The supermoon will bring unusually high tides because of its closeness and its alignment with the sun and Earth, but the effect will be modest, Chester said.

Moon will appear bigger Saturday Moon will appear bigger Saturday

The last supermoon, on March 19, 2011, was about 240 miles closer than this year's will be. Next year's will be a bit farther away than this year's.

But no matter how far away a full moon is, it's not going to make people kill themselves or others, commit other crimes, get admitted to a psychiatric hospital or do anything else that popular belief suggests, a psychologist says.

Studies that have tried to document such connections have found "pretty much a big mound of nothing, as far as I can tell," said Scott Lilienfeld of Emory University.

Lilienfeld, an author of "50 Great Myths of Popular Psychology," said the notion of full moons causing bizarre behavior ranks among the top 10 myths because "it's so widely held and it's held with such conviction."

"It's not a super-big deal," Rice said. "But anything that gets people outside and looking up at the night sky is a pretty big deal."

8 Comments

This story is closed for comments.

Oldest First
View all
  • Rdubya May 4, 2012

    I'm a retired mental health professional, and I can say for certain a full moon does have significant effect on some people. "Full Moon Fever" is a fact, ask anyone in Law Enforcement

  • poohpdoo2002 May 4, 2012

    Look out! It's headed right for us!!!

  • See Chart May 4, 2012

    Though I am from N.Carolina ,I live & work in NYC for many decades , you cannot tell me that the full moon does not affect 9 million+ people on this little island, it sure does ,where did the so called experts do their research on the untoward effects of the full moon in Iceland?

  • mmtlash May 4, 2012

    watch out for those werewolves!

  • Ambygirl May 4, 2012

    I'll be relaxing in the pool with a nice cool something to sip watching it.........gonna be a great weekend folks!

  • Uhavenoclu May 4, 2012

    So what,I've seen many Big people do many large moons out the car windows over the years.Full moons in the sky happen all the time,sorry ladies size doesn't matter,except when we spend millions of dollars to the dime store scientists who don't know a thing.

  • Just Plain Common Sense May 4, 2012

    Respectfully, I disagree. Ive seen many things in my years, and crazy it does bring out. My 2 cents worth. everybody has an opinion.

  • JohnnyMcRonny May 4, 2012

    The lunatics will be out. Oh, wait, that's on Tuesday.