Why does the Harvest Moon look orange when it rises?
Actually, it’s not just during the Harvest Moon that this happens. You can see this on any full or nearly full moon as the moon is rising. And it’s for the same reason that sunsets are red and orange. The sun is shining all of the colors of the rainbow on to the moon, and the moon is reflecting all of those colors pretty evenly. [See graphics to the right. Click on each image to get a larger image.] When the moon is low, the reflected sunlight has to travel through more air than when the moon is high in the sky. Colors at the blue and violet end of the rainbow (spectrum) are easily scattered or bent (refracted) by the atmosphere. (That’s why the sky is blue: you’re seeing blue sunlight scattered in every direction.) So it’s the colors at the red and orange end of the spectrum that pass through the atmosphere and into your eyes.
