LiveScience has a story about a century long search to find a meteor crater.  About 790,000 years ago, a meteor hit the Earth and spread tektites, shiny black lumps of rock, over about 10% of the surface of the planet.  The tektites were found from Indonesia to eastern Antarctica and from the Indian Ocean to the western Pacific Ocean.  Now, scientists from the Jackson School Museum of Earth History at the University of Texas have published a paper in the journal Proceedings of the National Academy of Sciences, in which, they claim to have found the crater.

Geochemical analysis and local gravity readings told researchers that the crater lay in southern Laos on the Bolaven Plateau; the ancient impact was concealed under a field of cooled volcanic lava spanning nearly 2,000 square miles (5,000 square kilometers), the scientists reported in a new study. 

When a meteor hits Earth, terrestrial rocks at the impact site can liquefy from the intense heat and then cool into glassy tektites, according to the Jackson School Museum of Earth History at The University of Texas. Scientists can look at the abundance and locations of tektites to help locate an impact, even if the original crater is eroded or concealed, the study authors wrote.

In this case, there were plenty of tektites — so where was the crater? 

The force of the impact is thought to have created a rim measuring more than 300 feet (100 meters) tall, according to the study. Tektites from the impact were at their biggest and most abundant in the eastern part of central Indochina, but because the tektites were so widespread, previous estimates of the crater’s size ranged from 9 miles (15 km) in diameter to 186 miles (300 km), and the feature’s precise position remained uncertain even though scientists spent decades searching.