月亮的色泽

2022年5月15日

Colors of the Moon
Image Credit & Copyright: Marcella Giulia Pace

Explanation: What color is the Moon? It depends on the night. Outside of the Earth’s atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth’s atmosphere, though, the moon can appear quite different. The featured image highlights a collection of apparent colors of the full moon documented by one astrophotographer over 10 years from different locations across Italy. A red or yellow colored moon usually indicates a moon seen near the horizon. There, some of the blue light has been scattered away by a long path through the Earth’s atmosphere, sometimes laden with fine dust. A blue-colored moon is more rare and can indicate a moon seen through an atmosphere carrying larger dust particles. What created the purple moon is unclear — it may be a combination of several effects. The last image captures the total lunar eclipse of 2018 July — where the moon, in Earth’s shadow, appeared a faint red — due to light refracted through air around the Earth. Today there is not only another full moon but a total lunar eclipse visible to observers in North and South America — an occurrence that may lead to some unexpected lunar colorings.

Tomorrow’s picture: alien castle rocks

月亮的色泽
影像提供与版权: Marcella Giulia Pace

说明: 月亮是什么颜色的？这要看是在那个夜晚。从地球的大气层外头看过去，靠反射阳光绽放光芒的黝黑月亮，看起来是棕褐色的。不过，从地球大气里看出去，月亮看起来大不同。这幅主题影像，呈现一位天文摄影者在10年之中，从义大利的多个地点记录的满月之色泽。当月亮的色泽泛红或泛黄时，通常代表它位在地平线附近。因为此时的月光，在通过厚重、有时富含尘埃微粒的地球大气时，蓝光会受到散射滤除。如果见到相对罕见的泛蓝月亮，代表此时大气里的尘埃颗粒较大。不过，紫月的成因目前不明，或许是数个效应共同造就的景观。最末端的那轮满月，则是摄于2018年7月的月全食期间，当月亮滑入地球的影子里，受到被地球周围空气折射的阳光渲染而呈古铜色。今天不但可再见到另一轮满月，而且更有北美洲及南美洲观星者可见的月全食，届时或许又能见到一些预期之外的月面色泽。

明日的图片: alien castle rocks