UFO researcher believed that the Westall UFO sighting was actually a high altitude balloon.
Keith Basterfield spent many years investigating unusual phenomena. He examined the Westall incident and found evidence in the National Archives of the HIBAL program that could explain what witnesses saw. HIBAL used silver high altitude balloons to monitor radiation levels near nuclear tests sites in Australia. One of these balloons, with flight number 292, may have blown off course and could account for what the students and staff observed. Basterfield believed that this would also account for the government and military officers that appeared not long after the sighting. However, documentation for that launch has been unable to be recovered.