A large, bright fireball was seen streaking across the northern sky of Bangkok about 8.40am on Monday, leaving a trail of smoke, with sightings also reported in Korat and Kanchanaburi.
Excited netizens immediately began posting messages, photographs and video on social media.
In Bangkok reports came from many different localities, including the Khlong Tan intersection, Phetchaburi road, Victory Monument and Vibhavadi Ransit, Rama 9, Sukhumvit and Rama 4 roads.
Netizens in Kanchanaburi in the western part of the country also said they also saw the flaming object pass over.
The Kanchanaburi deputy governor said there was no report of a helicopter or aircraft crashed in the province. He assumed the light was the same fireball seen over Bangkok.
There were also reports on Twitter that the fireball was seen over Nakhon Ratchasima about the same time.
Jor Sor 100 radio cited an astronomer in reporting that the fireball might be a meteor streaking down through the atmosphere.
An official at the Bangkok Planetarium, however, said there had been no reports of a meteorite landing. Most meteors completely burn up in the atmosphere. If one did crash to earth, it would probably be noticed, he said.
What was seen across the sky this morning could be a burning balloon, the official suggested
However, information on the website satview.org suggested the flaming object was space debris falling back to earth.
Space junk Flock 1B-11 object number 40459U was due to burn through the atmosphere on its way to earth about that time, according to the website. http://www.satview.org/?sat_id=40459U
Saran Poshyachina, the deputy director of the National Astronomical Research Institute of Thailand, said the fireball could be a meteorite landing. But he also did not rule out the possibility it could be space junk.
Video clips and other evidence sent to the institute had been closely examined. It was believed the fireball was 80 to 120 kilometres above the earth, as it could be seen from many areas of Thailand.
"It was almost certainly a good-sized rock burning up in our atmosphere," Phil Plait, a former member of NASA's Hubble Space Telescope Team and science popularizer, told dpa.
"It only took two seconds or so for it to go from being visible to it flaring as it disintegrated. It may have had a steep angle of entry."