the southern Indian Ocean could have been carried from there to southwestern Australia. It was reported that low levels of iodine-131 (a short-half-life product of nuclear fission) were detected in sheep in the southeastern Australian States of Victoria and Tasmania soon after the event. Sheep in New Zealand showed no such trace. The Arecibo Observatory in Puerto Rico detected an anomalous ionospheric wave during the morning of 22 September 1979, which moved from the southeast to the northwest, an event that had not been observed previously. After the event was made public, the United States Department of Defense (DOD) clarified that it was either a bomb blast or a combination of natural phenomena, such as lightning, a meteor, or a glint from the Sun. The initial assessment by the United States National Security Council (NSC), with technical support by the Naval Research Laboratory in October 1979 was that the American intelligence community had "high confidence" that the event was a low-yield nuclear explosion, although no radioactive debris had been detected, and there were "no corroborating seismic or hydro-acoustic data". A later NSC report revised this position to "inconclusive" about whether a nuclear test had occurred. The report concluded that if a nuclear test had been carried out, responsibility should be ascribed to the South African weapons programme. Office of Science and Technology evaluation The Carter Administration asked the Office of Science and Technology Policy (OSTP) to convene a panel of instrumentation experts to re-examine the Vela Hotel 6911 data, and to attempt to determine whether the optical flash detected came from a nuclear test. The outcome was politically important to Carter, as his presidency and 1980 re-election campaign prominently featured the themes of nuclear nonproliferation and disarmament. The SALT II treaty had been signed three months earlier, and was pending ratification by the United States Senate, and Israel and Egypt had signed the Camp David Accords six months earlier. An independent panel of scientific and engineering experts was commissioned by Frank Press, who was the Science Advisor to president Carter and the chairman of the OSTP, to evaluate the evidence and determine the likelihood that the event was a nuclear detonation. The chairman of this science panel itself was Dr. Jack Ruina of the Massachusetts Institute of Technology, and also the former director of the U.S. Department of Defense's Advanced Research Projects Agency. Reporting in mid-1980, the panel noted that