Every year around the night of Wan Ok Phansa, at the end of the rains in late October, reddish glowing spheres rise out of the Mekong along roughly 250 km of river centred on Phon Phisai and go up a couple of hundred metres before they wink out. Reports run from a handful to thousands in a night, from sparks to the size of a basketball, and tens of thousands of people come to watch. What is actually happening is not settled. A 2002 documentary filmed Lao soldiers firing tracer rounds across the river, which would explain a lot, though a Lao government investigation in 2021 concluded it was extremely unlikely anyone fired a weapon on the night they monitored. Marsh phosphine has been proposed and criticised, because such gas would not ignite by itself at the speeds people describe. Plasma has been proposed and needs high-voltage equipment nobody has out there. Nong Khai Province.
Phon Phisai, Nong Khai, Thailand
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