Huge Impact Crater Found in Remote Congo
Expedition confirms a meteor hit central Africa millions of years ago.
(Related: "'Fresh' Crater Found in Egypt; Changes Impact Risk?")
The so-called Luizi structure was first described in a German geological report from 1919. But without further fieldwork, it was impossible to say for sure that the 10.5-mile-wide (17-kilometer-wide) feature had been made by a meteor impact.
On other planets, such as Mercury and Mars, it's easier to identify impact craters based only on their shapes, since these worlds no longer have geologic forces making major changes to their surfaces.
(Related: "Martian 'Lake Michigan' Filled Crater, Minerals Hint.")
But on Earth, many older craters have likely been erased by tectonic activity or erosion, while others are