2025年10月22日
莱蒙彗星掠过高塔特拉山脉
影像提供与版权: Tomáš Slovinský½ & Constantine Themelis
说明: 彗星莱蒙正在全球各地的摄影机前展现其迷人的风采。这颗引人注目的彗星C/2025 A6 (Lemmon)本周最接近地球，目前正展现出两条长尾巴：一条蓝色的离子尾和一条白色的尘埃尾。离子尾被不断变化的太阳风推离太阳，并展现由瞬间气体喷发量所形成的结构。它发光是因被高能量阳光游离而发光。尘埃尾则是被阳光推离彗星，并因反射阳光而闪耀。这张主题影像是由50张曝光照片增强合成的，全部摄于两天前斯洛伐克的姆利尼察（Mlynica）。前景中的山脉是高塔特拉山脉（High Tatras），它将斯洛伐克与波兰部分地分隔开来。尽管彗星莱蒙在长时间曝光的相机下才能看得最清楚，但日落之后，在北方的天空中，甚至肉眼透过西方的黑暗天空也依稀可见这颗释放冰块的天体。
明日的图片: open space
Due to the lapse in federal government funding, NASA is not updating APOD website. We sincerely regret this inconvenience.
由于美国联邦政府资金中断，NASA目前暂停更新APOD网站。对此带来的不便，我们深感抱歉。
英文原文:
Explanation: Comet Lemmon putting on a show for cameras around the globe. Passing nearest to the Earth this week, the photogenic comet C/2025 A6 (Lemmon) is now extending two long tails: a blue ion tail and a white dust tail. The ion tail is pushed away from the Sun by the ever-present by ever-changing solar wind, and shows structure also created by how much gas is ejected at any one moment. It glows because it is ionized by high energy sunlight. The dust tail is pushed away from the comet by sunlight and shines by reflecting sunlight. The featured image is an enhanced composite of 50 exposures all taken two days ago from Mlynica, Slovakia. The mountains in the foreground are the High Tatras that partly separate Slovakia from Poland. Although Comet Lemmon is best visible in long camera exposures, the shedding ice ball has become faintly visible in northern skies even to unaided eyes through dark skies toward the west after sunset.
