保护地球，探索宇宙，发现文明
2021年11月30日 In Motion: Uranus and Moons Video Credit: David Campbell (U. Hertfordshire), Bayfordbury Observatory Explanation: What’s that moving across the sky? A planet just a bit too faint to see with the unaided eye: Uranus. The gas giant out past Saturn was tracked earlier this month near opposition — when it was closest to Earth and at its b...
NGC 6891 is a bright, asymmetrical planetary nebula in the constellation Delphinus, the Dolphin. This Hubble image reveals a wealth of structure, including a spherical outer halo that is expanding faster than the inner nebula, and at least two ellipsoidal shells that are orientated differently. The image also reveals filaments and knots in the nebula’s inter...
2021年11月29日 The Extraordinary Spiral in LL Pegasi Image Credit: NASA, ESA, Hubble, HLA; Processing & Copyright: Jonathan Lodge Explanation: What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected....
2021年11月28日 A High Cliff on Comet Churyumov-Gerasimenko Image Credit & Licence: ESA, Rosetta spacecraft, NAVCAM; Additional Processing: Stuart Atkinson Explanation: This high cliff occurs not on a planet, not on a moon, but on a comet. It was discovered to be part of the dark nucleus of Comet Churyumov-Gerasimenko (CG) by Rosetta, a robotic spacecraft l...
2021年11月27日 Messier 101 Image Credit: NASA, ESA, CFHT, NOAO; Acknowledgement – K.Kuntz (GSFC), F.Bresolin (U.Hawaii), J.Trauger (JPL), J.Mould (NOAO), Y.-H.Chu (U. Illinois) Explanation: Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier’s famous catalog, but definitely not one of the least. About 170,000 light-years ...
In a first, astronomers may have seen light from the merger of two black holes, providing opportunities to learn about these mysterious dark objects. 天文学家们首次看到了来自两个黑洞合并产生的光线，为了解这些神秘的黑暗物体提供了机会。 This artist’s concept shows a supermassive black hole surrounded by a disk of gas. Embedded in this disk are two smaller black holes that may have merged togethe...
2021年11月26日 Great Refractor and Lunar Eclipse Image Credit & Copyright: Laurie Hatch Explanation: Rain clouds passed and the dome of the Lick Observatory’s 36 inch Great Refractor opened on November 19. The historic telescope was pointed toward a partially eclipsed Moon. Illuminated by dim red lighting to preserve an astronomer’s night visio...
2021年11月25日 At the Shadow’s Edge Image Credit & Copyright: Jean-Francois Gout Explanation: Shaped like a cone tapering into space, the Earth’s dark central shadow or umbra has a circular cross-section. It’s wider than the Moon at the distance of the Moon’s orbit though. But during the lunar eclipse of November 18/19, part of the ...
Mounded, luminous clouds of gas and dust glow in this Hubble image of a Herbig-Haro object known as HH 45. Herbig-Haro objects are a rarely seen type of nebula that occurs when hot gas ejected by a newborn star collides with the gas and dust around it at hundreds of miles per second, creating bright shock waves. In this image, blue indicates ionized oxygen (...
影像来源：NASA 美国东部时间周三凌晨1点21分，NASA的双小行星重定向测试（DART）由SpaceX猎鹰9号火箭在加利福尼亚州范登堡太空基地东四号航天发射中心发射，这是世界上首个全面测试保护地球免受小行星或彗星威胁技术的任务。 DART只是NASA更大的行星防御战略的一部分，它由位于马里兰州劳雷尔的约翰霍普金斯应用物理实验室（APL）建造和管理，DART将撞击一颗对地球没有威胁的已知小行星。它的目标是稍微改变该小行星的运动，其方式可以用地面望远镜准确测量。 DART将展示航天器可以自主导航到目标小行星并有意与其发生碰撞——一种称为动能撞击的偏转方法。该测试将提供重要数据，帮助更好地为可能对地球构成冲击危险的小行星做好准备。LICIACube是一颗由意大利航天局（ASI）提供的立方体卫星，与DART一起运行...