UFO over Antarctica

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.

[link to news.yahoo.com]