time, but many thousands of miles away in a different hemisphere of the Earth. A test in Western Australia conducted a few months later found some increased nuclear radiation levels. A detailed study done by New Zealand's National Radiation Laboratory found no evidence of excess radioactivity, and neither did a U.S. Government-funded nuclear laboratory. Los Alamos National Laboratory scientists who worked on the Vela Hotel program have professed their conviction that the Vela Hotel satellite's detectors worked properly. Leonard Weiss, at the time Staff Director of the Senate Subcommittee on Energy and Nuclear Proliferation, has also raised concerns about the findings of the Ad-Hoc Panel, arguing that it was set up by the Carter administration to counter embarrassing and growing opinion that it was an Israeli nuclear test. Specific intelligence about the Israeli nuclear program was not shared with the panel whose report therefore produced the plausible deniability that the administration sought. Possible responsible parties If a nuclear explosion did occur, it occurred within the 3,000-mile-wide (4,800 km diameter) circle covering parts of the Indian Ocean, the South Atlantic, the southern tip of Africa, and a small part of Antarctica. Israel Well before the Vela incident, American intelligence agencies had made the assessment that Israel probably possessed its own nuclear weapons. According to journalist Seymour Hersh, the detection was the third joint Israeli-South African nuclear test in the Indian Ocean, and the Israelis had sent two IDF ships and "a contingent of Israeli military men and nuclear experts" for the test. Author Richard Rhodes also concludes the incident was an Israeli nuclear test, conducted in cooperation with South Africa, and that the United States administration deliberately obscured this fact in order to avoid complicating relations with South Africa and Israel. Likewise, Leonard Weiss offers a number of arguments to support the test being Israeli, and claims that successive U.S. administrations continue to cover up the test to divert unwanted attention that may portray its foreign policy in a bad light. Similarly, Professor Avner Cohen concluded that in hindsight, the existence of a cover-up by the United States is unambiguous because there were "at least three independent scientific pieces of evidence unrelated to a satellite that confirm the existence of the explosion." In the 2008 book The Nuclear Express: A Political History of the Bomb and its Proliferation, Thomas C. Reed and Danny B. Stillman stated their opinion that the "double