NASAのインスタグラム(nasagoddard) - 10月10日 22時51分

Today's @dictionarycom Word of the Day is "astrobleme," a scar on Earth's surface produced by the impact of a meteorite or asteroid.

Lake Manicouagan in northern Quebec, Canada, lies in one of the largest impact craters still preserved on Earth's surface. The lake itself surrounds a central uplift of the impact structure, which is about 70 kilometers in diameter and composed of broken fragments of minerals and rock. Overtime glaciation and other erosional processes have reduced the size of the crater.

The impact that formed Manicouagan is thought to have occurred about 212 million years ago, and some scientists believe it may have been responsible for a mass extinction that wiped out more than half of all living species. Today Lake Manicouagan serves as a reservoir and is one of Quebec's most important regions for Atlantic salmon fishing.

Credit: NASA/GSFC/LaRC/JPL, MISR Team
#astrobleme #manicouagan #earth #science #wordoftheday

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