2024年01月23日:深空星云影像：从海鸥到加州-（Deep Nebulas: From Seagull to California） [2024年01月23日:深空星云影像：从海鸥到加州-（Deep Nebulas: From Seagull to California）--原图下载](https://apod.nasa.gov/apod/image/2401/SeagullToCalifornia_Symon_2000.jpg"onMouseOver="if (document.images)document.imagename1.src='image/2401/SeagullToCalifornia_Symon_960_Annotated.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/2401/SeagullToCalifornia_Symon_960.jpg';){mtitle title="深空星云影像：从海鸥到加州"/}Image Credit & Copyright: Alistair Symon说明: 你对夜空的了解有多少？好的，那么你能从极深空影像里认出着名的天体吗？不论如何，先来个测验，看看你能否从这幅满布昏暗星云的深空影像里，找出一些着名的标誌性夜空天体。这幅影像里，有昴宿星团、巴纳德环、马头星云、猎户大星云、蔷薇星云、锥状星云、参宿七、水母星云、猴头星云、火焰星星云、蝌蚪星云、毕宿五、Simeis 147（义大利麵星云）、海鸥星云、及加州星云。至于它们的真实位置，可参考这张稍带注释的影像。辨认出它们的工作之所以颇有难度，其原因与乍看非常幽暗的天空时，难以认出熟悉的星座雷同：因为我们的夜空织锦具有极深的隐藏複杂性。这幅摄于美国 亚利桑那州幽暗天空下、由总曝光时间超过800小时的28张照片组合而成的主题影像，就显现了部分的这种複杂性。{lamp/}原文：{mtitle title="Deep Nebulas: From Seagull to California"/}Image Credit & Copyright: Alistair SymonExplanation: How well do you know the night sky?OK, but how well can you identify famous sky objects in a very deep image?Either way, here is a test: see if you can find some well-known night-sky icons in a deep image filled with faint nebulosity. This image contains the Pleiades star cluster, Barnard's Loop, Horsehead Nebula, Orion Nebula, Rosette Nebula, Cone Nebula, Rigel, Jellyfish Nebula, Monkey Head Nebula, Flaming Star Nebula, Tadpole Nebula, Aldebaran, Simeis 147, Seagull Nebula and the California Nebula.To find their real locations, here is an annotated image version. The reason this task might be difficult is similar to the reason it is initially hard to identify familiar constellations in a very dark sky: the tapestry of our night sky has an extremely deep hidden complexity. The featured composite reveals some of this complexity in a mosaic of 28 images taken over 800 hours from dark skies over Arizona, USA.

2023年12月10日:金字塔山上空的北斗七星-（Big Dipper over Pyramid Mountain） [2023年12月10日:金字塔山上空的北斗七星-（Big Dipper over Pyramid Mountain）--原图下载](https://apod.nasa.gov/apod/image/2312/BigDipperMt2_Cullen_1365.jpg"onMouseOver="if (document.images)document.imagename1.src='image/2312/BigDipperMt2_Cullen_960_annotated.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/2312/BigDipperMt2_Cullen_960.jpg';){mtitle title="金字塔山上空的北斗七星"/}Image Credit & Copyright: Steve Cullen说明: 你是何时学会如何辨识这个星官的？虽然它们是世界各地都很熟悉的一群恒星，不过，不同文化的人赋予它们不同的意象和传说。在美国，它们称为大勺子，是国际天文联盟在1922年划定的大熊座之一部分。其成员的星名，由左到右分别是摇光、开阳、玉衡、天权、天玑、天璇和天枢。当然，对某个星座而言，其成员未必有物理上的关联性。不过很意外的是，北斗七星大部分的成员在空间的运动，看似都朝同一个方向移动，而附近更大区域里的其他恒星，移动的方向也很相近。这个测定共同运动的特徵，指出它们可能都是平均约75光年远、宽30光年，名为大熊移动群这个邻近星团的成员。这张主题影像，呈现了悬在加拿大 亚伯达省金字塔山上空的这群标誌性恒星。（Alkaid 摇光、 Mizar/Alcor 开阳、 Alioth 玉衡、 Megrez 天权、Phecda 天玑、Merak 天璇、Dubhe 天枢）{lamp/}原文：{mtitle title="Big Dipper over Pyramid Mountain"/}Image Credit & Copyright: Steve CullenExplanation: When did you first learn to identify this group of stars?Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore.Known in the USA as the Big Dipper, the stars are part of a constellation designated by the International Astronomical Union in 1922 as the Great Bear (Ursa Major). The recognized star names of these stars are (left to right) Alkaid, Mizar/Alcor, Alioth, Megrez, Phecda, Merak, and Dubhe. Of course, stars in any givenconstellationare unlikely to be physicallyrelated.But surprisingly, most of the Big Dipper stars do seem tobe headed in the same direction as theyplough throughspace, a property they share with other stars spread outover an even larger area across the sky. Theirmeasured common motion suggests that they all belongto a loose, nearbystar cluster, thought tobe on average only about 75 light-years away and up to 30 light-years across.The cluster is more properly known as theUrsa MajorMoving Group.The featured image captured the iconic stars in 2017 above Pyramid Mountain in Alberta, Canada.

2023年12月05日:高能粒子撞击地球-（Energetic Particle Strikes the Earth） 2023年12月05日:高能粒子撞击地球-（Energetic Particle Strikes the Earth）--原图下载{mtitle title="高能粒子撞击地球"/}Illustration Credit: Osaka Metropolitan U./L-INSIGHT, Kyoto U./Ryuunosuke Takeshige说明: 这是迄今所知撞击地球的最高能量粒子之一，然而它从何而来的？以天照（神道教的太阳女神）为名的这颗粒子，就如其他撞击地球大气的宇宙射线一样，造成电子、质子和其他基本粒子的空气射丛喷洒到地球上。在这幅主题图示里，宇宙射线空气射丛撞击了位于美国 犹他州的望远镜阵列，而此阵列则于2021年5月记录到"天照事件"。宇宙射线空气射丛很常见，你很可能也曾被这种事件的粒子喷过，儘管你很可能不会查觉。这例高能粒子很可能是原子核，它的来源在二方面仍然是个谜。首先，我们不知道粒子或原子核如何能获得如此巨大的能量。其次，科学家试图回溯这颗粒子的来源，但并未找到任何可能的源头。（Amaterasu 天照； air shower 空气射丛）{lamp/}原文：{mtitle title="Energetic Particle Strikes the Earth"/}Illustration Credit: Osaka Metropolitan U./L-INSIGHT, Kyoto U./Ryuunosuke TakeshigeExplanation: It was one of the most energetic particles ever known to strike the Earth -- but where did it come from? Dubbed Amaterasu after the Shinto sun goddess, this particle, as do all cosmic rays that strike the Earth's atmosphere, caused an air shower of electrons, protons, and other elementary particles to spray down onto the Earth below.In the featured illustration, a cosmic ray air shower is pictured striking the Telescope Array in Utah, USA, which recorded the Amaterasu event in 2021 May. Cosmic ray air showers are common enough that you likely have been in a particle spray yourself, although you likely wouldn't have noticed. The origin of this energetic particle, likely the nucleus of an atom, remains a mystery in two ways.First, it is not known how any single particle or atomic nucleus can practically acquire so much energy, and second, attempts to trace the particle back to where it originated did not indicate any likely potential source.

2023年11月29日:堪萨斯州上空的陆龙捲-（A Landspout Tornado over Kansas） 2023年11月29日:堪萨斯州上空的陆龙捲-（A Landspout Tornado over Kansas）--原图下载{mtitle title="堪萨斯州上空的陆龙捲"/}Image Credit & Copyright: Brad Hannon说明: 龙捲风里头会再套着另一个龙捲风吗？通常来说，不会。好吧，那么宽大的尘捲风（尘暴）能套着龙捲风吗？不可能，理由很简单，因为龙捲风从天而降，但尘捲风则是拔地而起。这幅主题影像所呈现的是陆龙捲，这是一种不寻常型态的龙捲风，偶而会出现猛烈的雷暴系统之边缘。这例陆龙捲，则是由一位经验丰富的追风者，于2019年6月在美国 堪萨斯州拍摄及辨认。最中心的是真正的龙捲风，而其外鞘可能是由中心龙捲风抛出的大量尘埃所聚成的。截自目前为止，唯一确定会产生龙捲风的行星是地球，不过太阳表面也有类似龙捲风的活动，此外，尘捲风在火星上很常见。(landspout 陆龙捲){lamp/}原文：{mtitle title="A Landspout Tornado over Kansas"/}Image Credit & Copyright: Brad HannonExplanation: Could there be a tornado inside another tornado?In general, no. OK, but could there be a tornado inside a wider dust devil?No again, for one reason because tornados comes down from the sky, but dust devils rise up from the ground.What is pictured is a landspout, an unusual type of tornado known to occur on the edge of a violent thunderstorm.The featured landspout was imaged and identified in Kansas, USA, in June 2019 by an experienced storm chaser. The real tornado is in the center, and the outer sheath was possibly created by large dust particles thrown out from the central tornado.So far, the only planet known to create tornados is Earth, although tornado-like activity has been found on the Sun and dust devils are common on Mars.

2023年11月01日:犹他州上空的日环食-（Annular Solar Eclipse over Utah） 2023年11月01日:犹他州上空的日环食-（Annular Solar Eclipse over Utah）--原图下载{mtitle title="犹他州上空的日环食"/}Image Credit & Copyright: MaryBeth Kiczenski说明: 在上个月中旬，部分的太阳消失，不过却鲜少有人担心。日盘之所以会发生缺角，甚至从某些地方看出去，整个太阳中心都不见了，其实是太阳藏在月亮的后头所产生的日环食景观。在这幅摄于月亮追过东升旭日期间的主题日食影像序列里，前景的山丘是美国．犹他州的工厂丘。此外，从太阳伸出的辐射光束并不是真的，它们是因相机光圈所产生的、名为太阳星的衍射景象。其中的月亮倒是真的，只不过也经为人为增亮以强化其轮廓，让读者更容易辨识此次火之环食期间月亮位置的变化。不管这个日食影像序列如何引人讚歎，然而对这位天文摄影者而言，这仅是练习作而已。原因何在？她希望借着此次经验，为2024年4月8日拍下北美洲日全食精采影像的工作预做热身。（Factory Butte 工厂丘）{lamp/}原文：{mtitle title="Annular Solar Eclipse over Utah"/}Image Credit & Copyright: MaryBeth KiczenskiExplanation: Part of the Sun disappeared earlier this month, but few people were worried.The missing part, which included the center from some locations, just went behind the Moon in what is known as an annular solar eclipse. Featured here is an eclipse sequence taken as the Moon was overtaking the rising Sun in the sky.The foreground hill is Factory Butte in Utah, USA.The rays flaring out from the Sun are not real -- they result from camera aperture diffraction and are known as sunstar.The Moon is real, but appears only in silhouette in this ring-of-fire eclipse.As stunning as this eclipse sequence is, it was considered just practice by the astrophotographer. The reason? She hopes to use this experience to better photograph the total solar eclipse that will occur over North America on April 8, 2024.

2023年10月16日:日食与环-（Eclipse Rings） 2023年10月16日:日食与环-（Eclipse Rings）--原图下载{mtitle title="日食与环"/}Image Credit & Copyright: Jerry Zhang (left), Baolong Chen (photographer) & Amber Zhang (right)说明: 除了那个大问题，她什么都知道。她很清楚，从他们开车前去的目的地--奥勒冈州的阿伯特湖，可以看到日环食的完整过程。她也知道得再等16年，日环食才会再次出现在美国，所以这是一次难得的机会。她对规划很满意：她和男友将以剪影之姿出现在太阳的前方，有时单独，有时则是一起。她了解这次日食的环食阶段只有短短的数分钟，而她也花了很多时间参与规画。她见到他们的友人，在大约400米外的山脊下方架好了相机。她唯一不知道的，是自己会遇到决定终身的大问题。不过，她倒是知道问题的答案：我愿意。{lamp/}原文：{mtitle title="Eclipse Rings"/}Image Credit & Copyright: Jerry Zhang (left), Baolong Chen (photographer) & Amber Zhang (right)Explanation: She knew everything but the question.She was well aware that there would be a complete annular eclipse of the Sun visible from their driving destination: Lake Abert in Oregon. She knew that the next ring-of-fire eclipse would occur in the USA only in 16 more years, making this a rare photographic opportunity. She was comfortable with the plan: that she and her boyfriend would appear in front of the eclipse in silhouette, sometimes alone, and sometimes together. She knew that the annular phase of this eclipse would last only a few minutes and she helped in the many hours of planning. She could see their friend who set up the camera about 400 meters away at the bottom of a ridge. What she didn't know was the question she would be asked.But she did know the answer: "yes".