Tenoumer impact crater, Mauritania
author: Nasa/Novapix
reference: t-cra05-20001
Image Size 300 DPI: 47 * 31 cm
Tenoumer impact crater, Mauritania, as seen by the International Space Station in august 2018. Nearly a perfect circle, it is 1.9 kilometers (1.2 miles) wide, and sports a rim 100 meters (330 feet) high. The crater sits in a vast plain of rocks so ancient they were deposited hundreds of millions of years before the first dinosaurs walked the Earth. Modern geologists long debated what caused this crater, some of them favoring a volcano. But closer examination of the structure revealed that the crater's hardened `lava` was actually rock that had melted from a meteorite impact. Although it resides in ancient rock, Tenoumer is geologically young, ranging in age between roughly 10,000 and 30,000 years old.