Look Up: Tonight, 'Supermoon' Is Closer To Earth

  • A supermoon rises behind wind turbines Saturday near Palm Springs, Calif.
    Hide caption
    A supermoon rises behind wind turbines Saturday near Palm Springs, Calif.
    David McNew/Getty Images
  • The full moon rises behind statues of angels fixed at the St. Isaak's Cathedral in St.Petersburg, Russia.
    Hide caption
    The full moon rises behind statues of angels fixed at the St. Isaak's Cathedral in St.Petersburg, Russia.
    Dmitry Lovetsky/AP
  • Tourists look at the moon rising over the ancient temple of Poseidon at cape Sounion, south of Athens.
    Hide caption
    Tourists look at the moon rising over the ancient temple of Poseidon at cape Sounion, south of Athens.
    Aris Messinis/Getty Images
  • Almost full moon behind the cross of the Frauenkirche (Church of Our Lady) in Dresden, eastern Germany, on May 4, 2012.
    Hide caption
    Almost full moon behind the cross of the Frauenkirche (Church of Our Lady) in Dresden, eastern Germany, on May 4, 2012.
    Robert Michael/GettyImages
  • The full moon rises behind a steeple with cross of Ayia Thekla (Saint Thekla) Christian Orthodox church near coastal resort of Ayia Napa, Cyprus.
    Hide caption
    The full moon rises behind a steeple with cross of Ayia Thekla (Saint Thekla) Christian Orthodox church near coastal resort of Ayia Napa, Cyprus.
    Petros Karadjias/AP
  • The moon is seen over the landmark Chhatrapati Shivaji Terminus in Mumbai, India, on Saturday.
    Hide caption
    The moon is seen over the landmark Chhatrapati Shivaji Terminus in Mumbai, India, on Saturday.
    Rajanish Kakade/AP
  • The full moon rises behind a steeple with crosses of an Orthodox church in the town of Novogrudok, Belarus.
    Hide caption
    The full moon rises behind a steeple with crosses of an Orthodox church in the town of Novogrudok, Belarus.
    Sergei Grits/AP
  • The moon shines bright over Tokyo, Japan.
    Hide caption
    The moon shines bright over Tokyo, Japan.
    HAMACHI!/Flickr Creative Commons
  • The moon hangs over Chevy Chase, Md., Saturday night.
    Hide caption
    The moon hangs over Chevy Chase, Md., Saturday night.
    Mandel Ngan/AFP/GettyImages

1 of 9

View slideshow i

Head outside at sunset tonight and look up at the sky. If the full moon seems a tad larger than normal to you, that means one of two things: You are exceptionally perceptive, or you were already expecting to be dazzled, after hearing some of the buzz about this year's "supermoon."

It turns out that all full moons are not created equal. That's because the moon's orbit around the Earth isn't a perfect circle — it's an ellipse. And tonight, we're in luck.

"We will have moon closest to the Earth at the exact moment, or within a minute or two of when it becomes full," says Andrew Fraknoi at Foothill College in Los Altos, Calif., and senior educator at the Astronomical Society of the Pacific. "And this has no cosmic danger or significance but it means the moon will be a little bit brighter and a little bit bigger in our sky."

Fraknoi says this supermoon is a good excuse to take a romantic stroll. And for the best Hollywood effect, head out around sunset, when the moon is close to the horizon.

"When you look at the moon on the horizon, especially when there are buildings in the distance, it looks huge," he says. "And because this supermoon will be a tiny bit bigger, it will be an especially interesting moon illusion this Saturday night."

The moon illusion is simply a trick of the eye, but a convincing one.

Beachgoers know that high tides are higher and low tides are lower around full moons. The supermoon does add a bit of an extra tug, since it's a little bit closer to Earth than usual.

"But the difference of it being a little bit closer in its orbit or a little bit farther is only a question of about an inch in the height of the water," Fraknoi says.

So if you were expecting a supermoon to rock your world, sorry. You'll have better luck waiting for a giant asteroid to smash into our planet.

But there is a darker side to this story. Fraknoi says it used to be that events like supermoons and planetary conjunctions were 100 percent happy news, "but now more and more, I think partly because of tabloid television, when something is happening in the sky, it leads people to be afraid. Astronomer David Morrison has coined this new phrase called 'cosmophobia.' "

Since sunlight falls on all the moon's surface at some point, astronomers will tell you that the moon does not actually have a dark side — despite what we learned from Pink Floyd. But the human mind apparently does.

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.