Look Up: Tonight, ‘Supermoon’ Is Closer To Earth

The statue of Freedom, atop of the U.S. Capitol Building, is pictured against a “supermoon” on March 19, 2011.

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.