Firefighters in Maryland have had to backtrack after blaming a meteorite for a brush fire.
An astronomy lecturer told the BBC the “little old rock” was not to blame.
Rocks are poor conductors of heat and although they cause fireballs when they streak through the Earth’s atmosphere from space, even recent large meteor falls have not started fires.
The Bowie Volunteer Fire Department apologised and said the Twitter post “should have never been made”.
The blaze took 15 firefighters four hours to put out and left a crater 12-15 ft (3.7-4.6m) wide and 5-6 ft deep.
Afterwards, a tweet was sent out from the Bowie Volunteer Fire Department account showing a photograph of a crater and a rock, calling it a “possible meteorite strike”.
But Greg Redfern, an astronomy lecturer and Nasa ambassador, told the BBC a rock could not be called a meteorite before it is tested by a specialist laboratory.
And, he said, people’s perceptions of meteorites were not quite right.
“People have this vision that a meteorite is going to be hot and flaming and it is such a wrong notion,” he said.
“When a meteorite has come through the atmosphere it is cooled off way up high. I can’t give you a temperature but it would be cool to touch, maybe even cold.”
Three years ago, space rocks fell over Russia, injuring nearly 1,000 people but there was no ground fire.
Rocks that enter the Earth’s atmosphere from space partially burn up in the air but when they hit the ground they are cold.
Mr Redfern said: “The bottom line is that the fire in Maryland was not caused by that little old rock.”
Jonathan Howard of the Bowie Volunteer Fire Department promised in a statement that measures would be taken to ensure there was no repeat of the mistaken report.