The fireball seen streaking across the southwestern U.S. sky Wednesday night probably incinerated before striking the ground, an expert told The Times.
Thousands of people from Phoenix to Los Angeles reported seeing what they believed was a bright-green meteor.
But the object was probably a "near-earth asteroid" no bigger than a basketball, said Don Yeomans, a Jet Propulsion Laboratory Fellow who manages NASA's Near Earth Object Program.
"It's sort of Mother Nature's shot across the bow," he said. "It's an impressive light show, one of Mother Nature's best."