The fiery green light that rocketed across the sky Wednesday night probably was a fireball or bright meteor that disintegrated before it hit the ground, according to NASA experts.
The fiery light was seen over the southwestern United States. Residents in Phoenix, Las Vegas and Southern California reported seeing the object.
"We can't say 100 percent, but it's almost certain that the object was a fireball or very bright meteor,'' said Don Yeomans, manager of NASA's Near-Earth Object Program.
He said the object was probably about the size of a basketball or baseball. It likely disintegrated before it hit the ground.
Witnesses reported seeing the object at about 7:30 p.m. It moved west to east.
"I was talking to my friend and said, Oh My God, I'm watching something. I don't know what it is? It's not a UFO, but it's something falling from the sky, like on fire," said Marty Styles, who watched the light in Southern California.
The blue-green color suggests the object contained magnesium of nickel, Yeomans said. Other witnesses said it glowed orange, which indicated it entered earth's atmosphere at several miles per second, he said.
Such events are not as common as shooting stars, but they occur on a weekly basis, he added. The fireballs are usually seen flying over the ocean.
The FAA confirmed there were no aircraft incidents in the Western region. The FAA and the National Weather Service said they have received many calls.