A Waxing Crescent Moon lit up by earthshine
Earthshine is a dull glow which lights up the unlit part of the Moon because the Sun’s light reflects off the Earth's surface and back onto the Moon.
It is also sometimes called ashen glow, the old Moon in the new Moon's arms, or the Da Vinci glow, after Leonardo da Vinci, who explained the phenomenon for the first time in recorded history.
Earthshine is best seen a few days before and after a New Moon, right after sunset or before sunrise. Scientists studying global warming found that earthshine is more intense in April and May.
