Look up at the moon on a clear night this week and you might see something strange: the entire moon glowing faintly even though it's a thin crescent. The dark portion isn't actually dark. it's glowing with a ghostly light that makes the full circle of the moon visible against the night sky.
This is Earthshine, one of the few times when the new moon becomes the main event instead of the full moon. We spend so much time chasing full moons that we completely overlook this: the quiet, strange version that only shows up a few days a year.
