No. 116: Mar-Apr 1998
Those basketball-sized lights erupting from the Mekong River, Thailand, (SF#114) turn out to be a well-known annual event. Their official name is: the Nekha Lights. They have even been filmed and shown on Thai TV. These weird luminous displays occur during the October full moon and last only about 30 minutes. The lights rise out of the river and nearby rice paddies, but only along a small stretch of the river straddling the Thailand-Laos border.
(Anonymous; "Mekong Mystery," New Scientist, p. 109, December 20/27, 1997.)
Comment. Some marine species, such as the paolo worms, rise to the surface annually to spawn under a full moon. Could the Mekong Lights have a biological origin?