The Moon is a thin crescent in the dawn sky tomorrow. The Sun lights up only about one-tenth of the lunar hemisphere that faces our way. That’s the part of the Moon where it’s daylight. It’s nighttime across the rest of the disk.
But that doesn’t mean you can’t see that part of the Moon. It forms a ghostly presence, illuminated by earthshine – sunlight reflecting off of Earth. And the earthshine is pretty bright now, because Earth would appear 90 percent “full.” Because our planet is much bigger and more reflective than the Moon, it shines many times brighter than a full Moon appears from Earth. Tomorrow, the earthshine will be so intense that you can easily make out lunar features through a pair of binoculars.
And because the same side of the Moon always faces Earth, our planet sticks around in the same spot in the lunar sky, day and night. So future Earthwatchers will see it go through an entire cycle of phases every 29 and a half days, just as the Moon does. But from any given spot on the Moon, Earth won’t move – it’ll be “locked” at the same point in the sky.
Look for the crescent Moon in the east beginning an hour or two before dawn. It has a bright companion: Regulus, the star that marks the heart of the lion. It stands close to the right or upper right of the Moon. The Moon will be an even thinner crescent on Monday, but still easy to make out – thanks to the light of the silvery Earth.
Script by Damond Benningfield