28 junho 2007

Lua cheia


Summer Moon Illusion: On Saturday night, June 30th, step outside at sunset and look around. You'll see a giant moon rising in the east. It looks like Earth's moon with the usual craters and seas, but something's wrong. This full moon is strangely inflated. It's huge!
You've just experienced the Moon Illusion. [...]
This weekend's full moon hangs lower in the sky than any other full moon of 2007, so the Moon Illusion is going to be strong. What makes the moon so low? Consider the following: The sun and full moon lie on opposite sides of the sky. They are like a see-saw: when one is high, the other is low. Because the summer solstice was just last week (June 21st), the sun is near its highest point in northern skies. The full moon is correspondingly low.