从太空俯视马尼夸根陨撞击坑

从太空俯视马尼夸根陨撞击坑

Manicouagan Impact Crater from Space
Image Credit: NASA, International Space Station Expedition 59

Explanation: Orbiting 400 kilometers above Quebec, Canada, planet Earth, the International Space Station Expedition 59 crew captured this snapshot of the broad St. Lawrence River and curiously circular Lake Manicouagan on April 11. Right of center, the ring-shaped lake is a modern reservoir within the eroded remnant of an ancient 100 kilometer diameter impact crater. The ancient crater is very conspicuous from orbit, a visible reminder that Earth is vulnerable to rocks from space. Over 200 million years old, the Manicouagan crater was likely caused by the impact of a rocky body about 5 kilometers in diameter. Currently, there is no known asteroid with a significant probability of impacting Earth in the next century. Each month, NASA’s Planetary Defense Coordination Office releases an update featuring the most recent figures on near-Earth object close approaches, and other facts about comets and asteroids that could pose a potential impact hazard with Earth.

Tomorrow’s picture: explosion on the Sun

从太空俯视马尼夸根陨撞击坑
影像提供: NASA, International Space Station Expedition 59

说明: 2019年4月11日，在地球加拿大魁北克省上空400公里高轨道上飞行时，国际太空站的第59号远征队组员，拍下了这张广袤罗伦斯河及令人好奇的马尼 夸根环形湖之影像。在影像中右方的环形湖，是一座位于100公里直径、受到高度侵蚀的古老撞击坑遗迹内的现代水库。这个古撞击坑，除了是在轨道上清楚可见的结构之外，更可提醒我们地球是多么容易受到太空岩石的撞击。年龄超过2亿年的马尼夸根陨石坑，可能是由一颗直径大约5公里的石质天体所造成的。而据目前所知，在下个100年里，并没有任何已知的小行星具有撞击地球的显著机率。美国航空航天局的行星防卫协调辨公室，每个月都会发布一份通告更新通过地球附近的近地小行星之数量，及可能撞击危害地球的彗星和小行星的相关资讯。 （Manicouagan crater 马尼夸根撞击坑）

明日的图片: explosion on the Sun