Astronomy Picture of the Day——从空中看曼尼古根撞击陨石坑

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. But a fictional scenario to help practice for an asteroid impact is on going at the 2019 IAA Planetary Defense Conference.

从空中看曼尼古根撞击陨石坑

今年4月11日，位于加拿大魁北克上空400公里处的国际空间站的宇航员拍摄到了这幅快照，宽广的圣劳伦斯河和圆形的曼尼古根湖。图片中心的右面，这个环形的湖泊是一个古老的撞击陨石坑遗迹，其直径可达100公里。从轨道上看，这个古老的陨石坑非常明显，时刻提醒着人们，地球在来自空间的岩石面前是多么的脆弱。2亿多岁的曼尼古根陨石坑可能由直径约为5公里的岩石天体撞击而成。

高清原图地址：

https://apod.nasa.gov/apod/image/1905/iss059e019043.jpg

近期文章：

Astronomy Picture of the Day——带注释的银河中心

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Astronomy Picture of the Day——地球投在月球上的圆形影子

NASA

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