A video taken of the Antarctic research station Neumayer-Station III appears to show what some are calling a UFO over the South Pole.

The video posted to YouTube seems to show a round, blurry object floating above the station on Aug. 10. Speculation has run rampant, with conspiracy theorists and UFO buffs swapping explanations ranging from government collaboration with aliens to a top-secret test of some new cutting-edge secret weapon.

While a definitive explanation has not been found, several elements suggest a prosaic answer. The supposed UFO appears more or less directly over the research station; it also appears to be nearly perfectly round and about the right size for a balloon. Neumayer-Station III, a scientific research station, carries out tests and experiments in a wide variety of areas, including geophysics, meteorology and atmospheric chemistry. Weather balloons are used extensively to study and sample the atmosphere at different times and altitudes above Antarctica.

Weather balloon? To read more, click here.