Find the New Moon
Image Credit & Copyright: Mohamad Soltanolkotabi
Explanation: Can you find the Moon? This usually simple task can be quite difficult. Even though the Moon is above your horizon half of the time, its phase can be anything from crescent to full. The featured image was taken in late May from Sant Martí d’Empúries, Spain, over the Mediterranean Sea in the early morning. One reason you can’t find this moon is because it is very near to its new phase, when very little of the half illuminated by the Sun is visible to the Earth. Another reason is because this moon is near the horizon and so seen through a long path of Earth’s atmosphere — a path which dims the already faint crescent. Any crescent moon is only visible near the direction the Sun, and so only locatable near sunrise of sunset. The Moon runs through all of its phases in a month (moon-th), and this month the thinnest sliver of a crescent — a new moon — will occur in three days.
Tomorrow’s picture: noctilucent comet
影像提供与版权: Mohamad Soltanolkotabi
说明: 你找得到月亮吗？这种乍看很容易的任务，有时可变得极难。这是因为在每天之中，虽然月亮有一半的时间会悬在地平线之上，但它的位相可介于蛾眉和满相之间。这幅在今年5月底摄于西班牙Sant Martí d’Empúries，呈现地中海清晨的主题影像即可为例证。在影像里之所以找不到月亮，则是因为它很接近新月，从地球看出去，几乎见不到日矅半面的银白。另一重理由是因为月亮很接近地平线，所以蛾眉月的暗淡月光得穿过厚厚的地球大气，因此受到大幅减光。蛾眉月都出现在太阳的方位附近，所以只有在日出或日落时才得见。一个月相周期包含了所有的位相，而这个月最细窄的蛾眉月（新月）将在3天后现身。
明日的图片: noctilucent comet