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。
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…
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:…
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…
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:…
