NASA officials are saying Wednesday that the blast reported in the atmosphere over an Indonesian island on Oct. 8 was probably a small asteroid - about 10 meters in diameter - that detonated in the atmosphere. The force of the blast has been estimated at 50 kilotons - the equivalent of 100,000 tons of TNT.

There is You Tube video of the aftermath of the event. It shows what is described as a smoke trail left behind by the space rock's entry into the atmosphere, and some panic among the people on the ground.

Don Yeomans and other scientists with NASA's Near Earth Object program say the detonation was detected by sensors around the world - devices set up to detect low-frequency sound waves generated by atmospheric nuclear weapons testing.

"Assuming an estimated size of about 5-10 meters in diameter, we would expect a fireball event of this magnitude about once every 2 to 12 years on average. As a rule, the most common types of stony asteroids would not be expected to cause ground damage unless their diameters were about 25 meters in diameter or larger," they said.

The real question is why the Near Earth Object searches never spotted this object as it headed for our planet. 

Scientists are now tracking more than a thousand potentially threatening near-Earth asteroids. One of them passed the Earth on Oct. 17, skidding by inside the moon's orbit - less than 240,000 miles from the planet. It's size? About 35 kilometers in diameter.