2017年03月17日:金星的位相-（Phases of Venus）--原图下载
Image Credit &Copyright: Daniel Herron
说明: 就像月亮的月相会有变化，金星可见的日耀半球，也会有渐盈和渐亏的变化。这幅望远镜组合影像，呈现这颗内行星在西方天空以昏星之姿，于2016年12月20日到2017年3月20日之间，逐渐变大同时日耀面变窄的景象。在地球与太阳之间的内轨道绕行的金星，在这段期间之所以会变大，是因为它越来越靠近地球。而它的蛾眉相会变窄，则是因为金星越来越靠近地球往太阳的视线方向。在3月25日，金星会最接近地球─太阳的连线，并以8度左右的间距掠过太阳北方带来一次下合。紧接着，金星将会出现在清晨的东方天空，以晨星之姿绽放光芒。
明日的图片: ghostly lights
原文：
Image Credit &Copyright: Daniel Herron
Explanation: Just asthe Moon goesthrough phases,Venus' visible sunlit hemisphere waxesand wanes.Thiscomposite of telescopic images illustrates the steady changesfor the inner planet, seen in the west as the evening star,as Venus grows larger but narrows to a thin crescent fromDecember 20, 2016 through March 10.Gliding along its interior orbit between Earth and Sun, Venus growslarger during that period because it is approaching planet Earth.Its crescent narrows, though, as Venus swings closer to our line-of-sightto the Sun.Closest to the Earth-Sun line but passing about 8 degrees north of the Sunon March 25, Venus will reach a (non-judgmental)inferiorconjunction.Soon after, Venus will shine clearly above the eastern horizon inpredawn skies as planet Earth'smorning star.
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