瑞典上空的夜光云
See Explanation. Clicking on the picture will download the highest resolution version available.
请参阅说明。单击图片将下载可用的最高分辨率版本。
美国佛罗里达州上空的夜光云
A dawn sky is shown that is black at the top and brown near the horizon. Wispy clouds converge on the right turning from a white to a blue hue. Near the apex of this convergence is a crescent moon. Please see the explanation for more detailed information.
画面中展示的是黎明时分的天空，顶部是黑色，接近地平线的地方是棕色。右侧有几缕云彩汇聚在一起，颜色从白色逐渐变为蓝色。在汇聚的顶端有一弯新月。有关更多详细信息，请参阅说明。
亚得里亚海上空的新智彗星
2022年7月26日 Comet NEOWISE Rising over the Adriatic Sea Video Credit & Copyright: Paolo Girotti Explanation: This sight was worth getting out of bed early. Two years ago this month, Comet C/2020 F3 (NEOWISE) rose before dawn to the delight of northern sky enthusiasts awake that early. Up before sunrise on July 8th, the featured photographer was able to capture in dramatic fashion one of the few comets visible to the unaided eye this century, an inner-Solar System intruder that has become known as the Great Comet of 2020. The resulting video detailed Comet NEOWISE from Italy rising over the Adriatic Sea. The time-lapse video combines over 240 images taken over 30 minutes. The comet was seen rising through a foreground of bright and undulating noctilucent…
巴黎上空的夜光云
2022年7月12日 Noctilucent Clouds over Paris Credit & Copyright: Bertrand Kulik Explanation: It’s northern noctilucent cloud season. Composed of small ice crystals forming only during specific conditions in the upper atmosphere, noctilucent clouds may become visible at sunset during late summer when illuminated by sunlight from below. Noctilucent clouds are the highest clouds known and now established to be polar mesospheric clouds observed from the ground. Although observed with NASA’s AIM satellite since 2007, much about noctilucent clouds remains unknown and so a topic of active research. The featured image shows expansive and rippled noctilucent clouds wafting over Paris, France. This year, several northern locations are already reporting especially vivid displays of noctilucent clouds. Tomorrow’s picture: webb begins 巴黎上空的夜光云 影像提供与版权: Bertrand Kulik 说明: 这是北半球夜光云的季节。特定条件下才会形成于高层大气中的微小冰晶，在夏季末日落时受到下方阳光的照耀时，偶而会以夜光云之姿现身。夜光云是现知最高的云种，在地面观测中被归类为极地中层云。虽然自从2007年，NASA的中气层水冰特性观测卫星 (AIM)，就持续在观测它，但夜光云的特性仍有诸多不明之处，所以依然是很活耀的研究题目。这幅主题影像，呈现了带着波纹飘过法国巴黎上空的大片夜光云。在今年，已有数个北纬地区报导目暏了特别华丽生动的夜光云。 明日的图片:…
太空的边缘
2021年7月24日 The Edge of Space Image Credit & Copyright: Ralf Rohner Explanation: Where does space begin? For purposes of spaceflight some would say at the Karman line, currently defined as an altitude of 100 kilometers (60 miles). Others might place a line 80 kilometers (50 miles) above Earth’s mean sea level. But there is no sharp physical boundary that marks the end of atmosphere and the beginning of space. In fact, the Karman line itself is near the transition between the upper mesophere and lower thermosphere. Night shining or noctilucent clouds are high-latitude summer apparitions formed at altitudes near the top of the mesophere, up to 80 kilometers or so, also known as polar mesopheric clouds. Auroral bands of the northern (and southern) lights caused…
北半球夏季的暮光时分
2021年06月19日 Northern Summer Twilight Image Credit & Copyright: Justin Anderson Explanation: Nights grow shorter and days grow longer as the summer solstice approaches in the north. Usually seen at high latitudes in summer months, noctilucent or night shining clouds begin to make their appearance. Drifting near the edge of space about 80 kilometers above the Earth’s surface, these icy clouds were still reflecting the sunlight on June 14. Though the Sun was below the horizon as seen north of Forrest, Manitoba, Canada, they were caught in a single exposure of a near midnight twilight sky. Multiple exposures of the foreground track the lower altitude flash of fireflies, another fleeting apparition shining in the summer night. Tomorrow’s picture: the season’s sunrise 北半球夏季的暮光时分 影像提供与版权: Justin Anderson 说明:…
亚得里亚海上空的NEOWISE彗星
2020年7月13日 Comet NEOWISE Rising over the Adriatic Sea Video Credit & Copyright: Paolo Girotti Explanation: This sight was worth getting out of bed early. Comet C/2020 F3 (NEOWISE) has been rising before dawn during the past week to the delight of northern sky enthusiasts awake that early. Up before sunrise, the featured photographer was able to capture in dramatic fashion one of the few comets visible to the unaided eye this century, an inner-Solar System intruder that might become known as the Great Comet of 2020. The resulting video details Comet NEOWISE from Italy rising over the Adriatic Sea. The time-lapse video combines over 240 images taken over 30 minutes. The comet is seen rising through a foreground of bright and undulating noctilucent clouds, and…
夜光云
2020 June 19 The Veins of Heaven Image Credit & Copyright: Ruslan Merzlyakov (RMS Photography) Explanation: Transfusing sunlight through a darkened sky, this beautiful display of noctilucent clouds was captured earlier this week, reflected in calm waters from Nykobing Mors, Denmark. From the edge of space, about 80 kilometers above Earth’s surface, the icy clouds themselves still reflect sunlight, though the Sun is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the night shining clouds have made an early appearance this year as northern nights grow short. Also known as polar mesopheric clouds they are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by disintegrating meteors…
天空的脉络
2019 July 26 The Veins of Heaven Image Credit & Copyright: P-M Hedén (Clear Skies, TWAN) Explanation: Transfusing sunlight through a still dark sky, this exceptional display of noctilucent clouds was captured earlier this month, reflected in the calm waters of Vallentuna Lake near Stockholm, Sweden. From the edge of space, about 80 kilometers above Earth’s surface, the icy clouds themselves still reflect sunlight even though the Sun is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the night shining clouds have made a strong showing so far during the short northern summer nights. Also known as polar mesopheric clouds they are understood to form as water vapor driven into the cold upper atmosphere condenses on the…
夜光云、倒影与剪影
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…