It is probably the closest Australia has come to scrambling fighter jets to intercept a UFO. Documents that have just become available under the 30-year rule at the National Archives of Australia reveal how two RAAF Mirage jets were placed on the second highest level of alert to determine the cause of unidentified radar contacts seen on screens at Mascot.
The ''X Files'' viewed in Canberra also give details of other unexplained sightings, some of which are supported by witness statements to police. One caller dismissed it as a rock band's laser show.
In the Sydney alert, the papers stamped ''restricted'' tell how operation ''Close Encounter'' was launched by No.3 Control and Reporting Unit at RAAF Base Williamtown near Newcastle on June 30, 1983, after the phenomenon was first noticed earlier in the month.