We talk so much about the sun in eclipse, it’s easy to forget the moon will be at center stage on Monday. After all, during totality, we won’t see the sun. Instead we’ll be facing the new moon! No sunlight will touch the face of the moon visible from Earth, but from the perspective of someone standing on the moon and looking back, they’d see a Full Earth. Full Earth casts a lot of light, the reason that properly exposed photos of the sun during eclipse actually show details on the moon including the large dark spots called lunar seas.
Before any of this happens, the moon has one last appointment to keep. Tomorrow morning (Aug. 19), it will shine as a thin, waning crescent about 5° southeast of the planet Venus at dawn. Beautiful! Let it serve as a good omen for all of us hoping for a clear sky — or a least a few well-placed clearings — on eclipse day.
Stay calm and be safe in your travels.