This view from Dead Horse Point State Park near Moab in Utah was taken just before sunrise and shows, in addition to the moon setting, the penumbra. That dark line just above the horizon is actually the Earth’s shadow cast on the atmosphere. As the sun rises below the horizon, the penumbra recedes until, at sunrise, it disappears below the horizon. You see the same effect at sunset only then, the penumbra rises from the horizon after the sun has set. Take a look to the east next time you are out just after sunset and you’ll probably see it.
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