抬头看！26日将迎年度最小蛾眉月

Core Points - The article discusses the occurrence of the "smallest crescent moon" on September 26, 2023, and provides details on how to observe it [1][5] - The crescent moon appears twice in each lunar month, once between the new moon and the first quarter, and again between the last quarter and the new moon [2] - The term "smallest crescent moon" refers to the crescent moon's appearance when the moon is at its apogee, resulting in a smaller visual diameter [2] Summary by Sections - Crescent Moon Appearance - The crescent moon appears in a thin arc shape, resembling a woman's eyebrow, with opposite orientations during its two occurrences in a lunar month [2] - Lunar Distance and Size - The moon's orbit around the Earth is elliptical, varying in distance from over 400,000 kilometers at apogee to less than 360,000 kilometers at perigee, a difference of about 50,000 kilometers [2] - The smallest crescent moon occurs when the moon is near apogee, while the largest occurs near perigee [2] - Observation Recommendations - For optimal viewing, the public is advised to look southwest during sunset on September 25 and 26, as the crescent moon will appear like a reversed letter "C" [5] - Moonlight Reflection - The bright part of the moon is sunlight reflected, while the dim part is illuminated by sunlight reflected from the Earth, a phenomenon known as "earthshine" or "new moon holding the old moon" [6]