Let there be lights

Last October, a record 110 naga fireballs shot up into the air above the mighty Mekong. If you didn't see them last year, make sure you're in Phon Phisai - a district on the outskirts of Nong Khai - on October 12 and 13 or you'll again miss the chance to witness this amazing sight.

As vassa, the annual Buddhist rains retreat draws to a close, the Mekong River will again erupt with its mysterious fireballs. What are they? Join the never-ending debate and make up your own mind.

The phenomenon is as enigmatic as it is beautiful. Thousands of pink and red bursts of light - the so-called "naga fireballs" or "ghost fireballs" - rise from the Mekong in Nong Khai on the Thai-Lao border.

More like a sci-fi series than reality, the strange phenomenon happens only at this time each year, during the full moon of the 11th lunar month, which falls on October 13 in the old Laotian calendar.

The glowing spheres, the size of chicken eggs, hang in the air for a few minutes before disappearing, leaving in their wake astonishment, mystification and many, many questions.

Scam? A miracle? Why only at this time of the year? Why Nong Khai?

Manas Kanoksil, a local doctor turned "myth-buster" in Nong Khai, has been observing and studying the fireballs for more than 10 years. The science that he's applied tells him that the bizarre phenomenon is the combustion of natural gases released from the riverbed and heat drifting on the surface.

The combustion requires a complete set of perfectly natural occurrences, including the relative positions of the earth, sun and moon. Hence its occurrence on the last night of the Buddhist Lent.

However, the local people tend to be more interested in mythology than science,

Way back at the birth of legends, the story goes, Nong Khai and other settlements along the Mekong were created by the water serpents called nagas.

Only later was the saga imbued with Buddhist fancy: The Lord Buddha ascended to heaven for Lent to visit his mother, and his return during the full moon of the 11th lunar month was cause for rejoicing.

To show their delight, the nagas shot fireballs into the air.

The drama continues. A television crew once tried to convince witnesses that it was a hoax perpetrated by the Lao on the far side of the river. Unfortunately, the only proof was videotape of a few Lao firing their rifles into the air.

A painter living on the Thai bank, Manas Anuraksa, remains enchanted by the fireball phenomenon, regardless of the explanation.

"It's very peculiar, and we're not sure who or what causes it, but whatever it is, I believe this mythical event could make Nong Khai special enough to become a wonder of the world."

Manas is right. The sleepy little town, once known to visitors only as a place to get a cold beer before crossing the border to Laos, has become a popular destination thanks to the bizarre annual show.

The enigma has a spin-off as it always draws more than 300,000 visitors to Nong Khai. This year the locals are even throwing the six-day Phon Phisai World Naga Fireball Festival with a series of cultural shows.

One way to watch them is to rent a motorcycle and ride eastward along the Mekong from Muang district to Phon Phisai and Rattanawapee.

Ask around about the best spots to stop - the riverbanks get quite crowded in places - and keep your eyes peeled from 6 to 9pm.

There will also be religious ceremonies marking the end of the three-month Lenten retreat, plus long-tailed-boat races, fireworks and illuminated floats. Strictly sideshows, of course - you have to see the fireballs.