Light Dispersion by a Triangular Prism

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图注： This photograph shows a prism splitting a beam of white light into its component colors — a beautiful demonstration of optics, the branch of physics that studies how light behaves and interacts with materials. When white light enters the prism, different wavelengths (colors) bend by different amounts because of a process called refraction. This separation of colors produces a spectrum — similar to a rainbow — revealing that white light is actually made up of many colors combined going from blue, through green and yellow to red. Understanding optics helps scientists and engineers design lenses, microscopes, telescopes, cameras, and many other tools that shape and control light for practical use. The way the prism disperses light into a spectrum is the same principle that makes rainbows form in the sky when sunlight passes through raindrops.
来源： Kelvinsong
来源链接

词汇表: 光 , 光学 , 可见光谱

授权许可： CC0 1.0 通用 (CC0 1.0) 公共领域贡献 CC0 1.0 通用 (CC0 1.0) 公共领域贡献 图标

文件 ( 图像 777.82 kB)

冬季银河

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为 OAE 制作

图注： 2022 年国际天文学联合会 OAE 天体摄影比赛静态天体图案类获奖作品。 本影像摄于2019年2月意大利威尼托大区的密苏里纳湖（Lago di Misurina），呈现冬夜星空与雪原交辉的奇景。 银河弧光下，夜空中最亮的天狼星（Sirius/大犬座α）闪耀于东南方。在希腊神话中，这颗"燃烧者"隶属猎户座忠犬——大犬座（Canis Major）。其左侧的小犬座（Canis Minor）以"先犬星"（Procyon/南河三）为主导，该星名暗示其先于天狼星升起的特性。猎户座位于大犬座右侧，其标志性"腰带三星"清晰可辨。 猎户座右上方树冠处，金牛座的毕宿星团（Hyades）与昴星团（Pleiades）构成传说中的"天界之门"，此处恰为黄道与银河两大天球基准圈的交汇点。希腊神话中，金牛化身喻指宙斯诱拐腓尼基公主欧罗巴的传说。 金牛座上方银河弧缘，御夫座主星五车二（Capella）粲然生辉。这颗恒星在印度教中被视为创世神梵天之心，而巴西博罗罗原住民则将御夫座部分星群与邻座恒星共组"凯门鳄星座"。 金牛座右侧可见英仙座（Perseus），其内的英仙座h+χ双星团被古希腊人视为英雄珀尔修斯神剑的寒光。这位斩杀海怪、解救安德洛墨达的传奇人物，其故事经奥维德史诗流传至今。影像中同样可见呈W形的仙后座（Cassiopeia）——希腊诗人阿拉托斯笔下象征"天国之钥"的星群，在印度天文传统中对应莎米什塔公主，在泰国喻指蝙蝠，于阿拉伯古星象中则化身骆驼。 林木间隙处，肉眼可辨的仙女座星系（Andromeda Galaxy）静静悬浮。
来源： Giorgia Hofer/IAU OAE

词汇表: 仙女座星系 , 银河系 , 金牛座 , 昴宿星团
分类： 星系 , 银河系与星际介质 , 肉眼天文学

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

此文件在 Zenodo 上 ( 图像 1.18 MB)

Moon and Earth's thin atmosphere

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图注： Taken from the International Space Station (ISS), approximately 400 kilometers above the ground, the picture shows the Moon far in the background and Earth's thin atmosphere. It appears blue as light in this wavelength is scattered more than in others by the gases in the upper layers. The photo was taken in March 2015 by a crew member. Clearly visible is the vanishingly small layer of gases compared to Earth's dimensions. There is no clear border between the atmosphere and space; it is a smooth transition with no sharp edges. The thickness to the upper limit of the stratosphere, roughly 50 kilometers, does not even amount to one percent of Earth's radius. Above 600 kilometers, particles reaching the critical escape velocity can leave into space. The total mass of the atmosphere is around 300 times less than that of all oceans combined or one million times less than Earth's total mass.
来源： Earth Science and Remote Sensing Unit, NASA Johnson Space Center
来源链接

词汇表: 大气层
分类： 地球

授权许可： 公共领域 公共领域 图标

文件 ( 图像 3.99 MB)

The planet PDS 70b inside a protoplanetary disk

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图注： An image of the planet PDS 70b. The young star PDS 70b has a protoplanetary disk surrounding it. Disks like these contains gas, fine sandy particles that astronomers refer to as dust and also larger bodies ranging from objects the size of pebbles to protoplanets (planets that are still forming). This image was taken in infrared light using adaptive optics. Adaptive optics is a technique that uses flexible mirrors and computer analysis to remove the blurring effect of the Earth's atmosphere. This allows astronomers to search regions close to stars like PDS 70 that would otherwise be swamped by light from the star spread out by the Earth's atmosphere. In the center is a black circle. This is caused by a coronograph, a small circle that blocks out light from the parent star. This is surrounded by a bright oval, infrared light emitted from the material in the protoplanetary disk. To the right of the black circle covering the star is a bright dot. This is PDS 70b, a giant planet that is still forming .
来源： ESO/ A. Müller, MPIA
来源链接

词汇表: 行星形成 , 原行星 , 原行星盘 , 自适应光学
分类： 系外行星与天体生物学

授权许可： 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 知识共享许可协议 署名 4.0 国际 (CC BY 4.0) 图标

文件 ( 图像 1.59 MB)

ISS' view of nightly Japan

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图注： This nighttime photograph of Earth was taken from the International Space Station (ISS) by astronaut Scott Kelly in 2015 during Expedition 44. It captures the nation of Japan lit up after dark, with bright city lights tracing urban centers, major roadways, and densely populated regions. The view from orbit at night highlights how human activity shows up as patterns of light on Earth’s surface, with well-lit areas contrasting sharply against the surrounding darkness of rural regions and open water. Photographs like this highlight what “night” looks like from space — not just a lack of sunlight, but also a time when artificial light reveals the rhythms of human life across the globe. From hundreds of kilometers above the planet, the night side of Earth appears as a tapestry of glowing clusters and dark spaces, offering insight into population distribution, infrastructure, and how cities remain active long after sunset. The ISS’s low orbit allows astronauts to capture these detailed views of Earth after dark, helping us appreciate both natural and human elements of nighttime on our planet.
来源： NASA
来源链接

词汇表: 地球 , 夜

授权许可： 公共领域 公共领域 图标

文件 ( 图像 24.73 MB)