Colleen Dolan, age 11), New York for her question:

What makes the moon light up?

The sun lights up the moon  and the same old sun also lights up the earth. Let's picture what does on, way out there in space. The moon orbits around and around the earth. And while this happens, the moon and the earth orbit around the sun together. The sun is 93 million riles away, out there in the middle of the big orbit while the earth and moon dance around the sun, both of them spin around like tops, but the earth spins faster. It makes one spin every 24 hours and the moon takes almost a month to spin around once. As they spin, the earth and moon turn first one side, then another side to face the sun. The side facing  the sun is bathed in daylight. As the moon turns around, sunshine lights up first this side, then that side. This is what you see as the new moon grows to be a full moon.