A meteor lit up the sky over Botswana, Africa, early Saturday evening. Scientists discovered the six-foot-wide asteroid just hours before it reached Earth. NASA tracks 90 percent of near-Earth objects that are larger than 150 meters (~460 feet) in diameter, which means it misses lots of the smaller ones until they’re close by. This most recent rock, called 2018 LA, was spotted on June 2 by the Catalina Sky Survey in Arizona.