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Moon and Planets at Twilight Explanation: This week's ongoing conjunction of Venus and Jupiter may have whetted your appetite for skygazing. Tonight is the main course though. On November 28, a youngcrescent Moon will join them posing next to the two bright planets above the western horizon at twilight. Much like tonight's visual feast, this night skyscape shows a young lunar crescent and brilliant Venus in the western evening twilight on October 29. The celestial beacons are setting over distant mountains and the Minya monastery, Ganzi Tibetan Autonomous Prefecture, Sichuan, China, planet Earth. Then Mercury, not Jupiter, was a celestial companion to Venus and the Moon. The fleeting innermost planet is just visible here in the bright twilight, below and left of Venus and near the center of the frame. Tomorrow, November 29, the crescent Moon will also help you spot planet Saturn for dessert. 木卫二的重制影像 伽利略飞船在20世纪90年代末探测木星系统时拍摄了十分震撼的木卫二影像。它揭示了在这颗卫星的冰外壳下隐藏了一片全球性海洋（其深度至少是地球海洋的10倍）。这幅图像是原始的木卫二图像通过重制后的效果，新的校准技术使得这张影像能够展现人眼中真正的木卫二是什么样子。液态水就在上图那些断裂的冰层之下。被潮汐锁定的木卫二处在一个围绕木星公转的椭圆轨道上，这使得它有足够的热量可以维持地下海洋的存在。但更吸引人的是，即便在没有太阳光的情况下，木卫二在木星引力和潮汐作用的影响下依然有足够的能量可以支持生命的存在，这使得木卫二成为了地球之外最可能存在生命的星球之一。到底是什么样的生物才能在这片缺少阳光的地下深海中生存？也许是类似地球的耐热虾。 高清原图地址： https://apod./apod/image/1911/2019_10_29_Village_Moon_Venus_Mercury_1500px.png 近期文章： Astronomy Picture of the Day——猎户座 Astronomy Picture of the Day——暮色之下的月亮和行星 Astronomy Picture of the Day——哈勃展示的木星新肖像 NASA 微店 |
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