倒影

2020 June 24 Inverted City Beneath Clouds Image Credit & Copyright: Mark Hersch Explanation: How could that city be upside-down? The city, Chicago, was actually perfectly right-side up. The long shadows it projected onto nearby Lake Michigan near sunset, however, when seen in reflection, made the buildings appear inverted. This fascinating, puzzling, yet beautiful image was captured by a photographer in 2014 on an airplane on approach to Chicago’s O’Hare International Airport. The Sun can be seen both above and below the cloud deck, with the latter reflected in the calm lake. As a bonus, if you look really closely — and this is quite a challenge — you can find another airplane in the image, likely also on approach to the same airport. Tomorrow’s…

2020 May 28 Reflecting the International Space Station Image Credit & Copyright: Helmut Schnieder Explanation: Still bathed in sunlight, the International Space Station arced through the evening sky over lake Wulfsahl-Gusborn in northern Germany, just after sunset on March 25. The familiar constellation of Orion can be seen left of the trail of the orbital station’s bright passage. On the right, Venus is the brilliant evening star above the western horizon. With the camera fixed to a tripod, this scene was captured in a series of five exposures. How can you tell? The short time delay between the end of one exposure and the beginning of the next leaves small gaps in the ISS light trail. Look closely and you’ll also see that the sky…

2019 December 27 A Partial Solar Eclipse Sequence Reflected Image Credit & Copyright: Majid Ghohroodi Explanation: What’s happened to the Sun? Yesterday, if you were in the right place at the right time, you could see the Sun rise partially eclipsed by the Moon. The unusual sight was captured in dramatic fashion in the featured image not only directly, in a sequence of six images, but also in reflection from Soltan Salt Lake in Iran. The almost-white Sun appears dimmer and redder near the horizon primarily because Earth’s atmosphere preferentially scatters away more blue light. Yesterday’s partial solar eclipse appeared in the sky over much of Asia and Australia, but those with a clear enough sky in a thin band across the Earth’s surface were…

2019 August 5 A Total Solar Eclipse Reflected Image Credit & Copyright: Thierry Legault Explanation: If you saw a total solar eclipse, would you do a double-take? One astrophotographer did just that — but it took a lake and a bit of planning. Realizing that the eclipse would be low on the horizon, he looked for a suitable place along the thin swath of South America that would see, for a few minutes, the Moon completely block the Sun, both directly and in reflection. The day before totality, he visited a lake called La Cuesta Del Viento (The Slope of the Wind) and, despite its name, found so little wind that the lake looked like a mirror. Perfect. Returning the day of the eclipse, though,…

2019 June 26 夜光云、倒影与剪影 影像来源与版权: Peter Simmering 说明：有时候地面上是夜晚，但天空中是白天。当地球自转遮挡了太阳时，日落便从地面升起。因此，在地面上的日落时分，阳光仍然照耀着天空中的云层。在通常情况下，我们可以看到美丽的落日，但不同寻常的夜光云漂浮得如此之高，以至于在天黑后还能看到。夜光云通常太过黯淡而不会被人们看到，它们可能在夏季日落之后、当阳光从下方照耀时，才能显现出来。夜光云是已知最高的云层，它被认为是极地中间层云的一部分。这幅特征影像拍摄于两周之前，它呈现了荷兰.兹沃勒市北部遥远天空中的网状夜光云和一片小湖中的夜光云倒影，以及地平线上显著的树木剪影。这种异常明亮的夜光云不断出现在北欧的大部分地区。关于夜光云的多数发现都来自于过去十年，而它们是如何形成和演化的仍然是一个有待积极研究的课题。 Noctilucent Clouds, Reflections, and Silhouettes Image Credit & Copyright: Peter Simmering Explanation: Sometimes it’s night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above. Under usual circumstances, a pretty sunset might be visible, but unusual noctilucent clouds float so high up they can be seen well after dark. Normally too dim to be seen, they may become visible just after sunset during the summer when illuminated by sunlight from below. Noctilucent clouds are the highest clouds known and thought to be part of polar mesospheric clouds. Featured here as they appeared two…