December 1, 2010
Ball Lightning Responsible For UFO Sightings?
Australian astrophysicist Stephen Hughes said that some UFO sightings could be explained by ball lightning and other atmospheric phenomena, according to a recent BBC News report.
The scientists made a detailed study of an unusual event that took place in 2006 when large meteors were observed over Brisbane. During the same time, another unidentified green object was seen to roll over nearby mountains.Hughes has theorized that the object was actually ball lightning.
He believes that fireballs may have momentarily triggered an electrical connection between the upper atmosphere and the ground, providing energy for the ball lightning to appear above the hills.
He said that the extraordinary event is just the sort of things that might lead to people assuming they witnessed UFO activity.
"If you put together inexplicable atmospheric phenomena, maybe of an electrical nature, with human psychology and the desire to see something - that could explain a lot of these UFO sightings," he told BBC News.
Hughes initiated the study after being called in by the local TV station to look over and explain photos of the fireballs captured by eyewitnesses on camera phones.
Fireballs are exceptionally bright meteors and are produced by fragments of space rock larger than the sand-grain-sized particles responsible for shooting stars.
Three individual fireballs were reported to be seen on May 16, 2006 in Brisbane.
The Queensland University of Technology produced a survey of eyewitnesses, including a farmer who recalled seeing a luminous green ball rolling down a slope of the Great Divide.
The farmer described the object as being about a foot in diameter and it appeared to jump over some rocks and follow the path of a metal fence for "some minutes." He said he saw the green object come into view just after a fireball had passed overhead.
The farmer thought at first that he was witnessing a plane crash and called the police, but a search found no wreckage.
Hughes said that ball lightning seems an obvious explanation. Ball lightning is still not fully understood, but they are known to be associated with thunderstorm.
He said that the natural flow of current that exists between the uppermost reaches of the atmosphere, the ionosphere, and the ground was increased by the passage of the meteor that streamed charged particles and other conductive materials in its wake.
"Could it be that the meteor descending through the atmosphere, having passed through the ionosphere, actually created a transient conductive connection between the ionosphere and the ground, even if it was only for a few seconds? Was that enough to put charge into the ground, and then with the discharge form some kind of plasma ball above?
"Think of the ionosphere and the ground as the terminals on the battery and you put a wire between those two terminals and current flows, and literally you get a spark."
Other scientists believe that charges dissipating through the ground can create balls of glowing ionized gas above it.
Dr. John Abrahamson from the University of Canterbury, NZ, told BBC that ball lightning consisted of vaporized mineral grains kicked out of the soil by a conventional lightning strike, an idea that Brazilian researchers later tested.
Hughes said the work was "relatively feasible" and something that made "interesting connections."
"There's a long way to go before everyone will be happy and satisfied that we have a full solution," he told BBC News.
He wrote his explanation in a journal of the Royal Society.
On the Net:
- Queensland University of Technology
- Proceedings of the Royal Society A- Mathematical, Physical and Engineering Sciences