London <\/p>\n
ON the afternoon of Nov. 7, 2006, pilots and airport employees at
\nO\u2019Hare International Airport in Chicago saw a disc-like object hovering
\nover the tarmac for several minutes. Because nothing was tracked on
\nradar, the Federal Aviation Administration did not investigate. Yet
\nradar is not a reliable detector of all aircraft. Stealth planes are
\ndesigned to be invisible to radar, and many radar systems filter out
\nsignals not matching the normal characteristics of aircraft. Did it
\nreally make sense to entirely ignore the observations of several
\nwitnesses? <\/p>\n
A healthy skepticism about extraterrestrial space travelers leads
\npeople to disregard U.F.O. sightings without a moment\u2019s thought. But in
\nthe United States, this translates into overdependence on radar data
\nand indifference to all kinds of unidentified aircraft \u2014 a weakness
\nthat could be exploited by terrorists or anyone seeking to engage in
\nespionage against the United States.<\/p>\n
The American government has not investigated U.F.O. sightings since
\n1969, when the Air Force ended Project Blue Book, an effort to
\nscientifically analyze all sightings to see if any posed a threat to
\nnational security. Britain and France, in contrast, continue to
\ninvestigate U.F.O. sightings, because of concerns that some sightings
\nmight be attributable to foreign military aircraft breaching their
\nairspace, or to foreign space-based systems of interest to the
\nintelligence community. <\/p>\n
Most of the incidents investigated in Britain have been easily
\nexplained as misidentifications of stars and planets, aircraft lights,
\nsatellites and meteors, but some cases have raised national security or
\nair safety issues. <\/p>\n
On Dec. 26, 1980, for instance, several witnesses at two American
\nAir Force bases in England reported seeing a U.F.O. land. An
\nexamination of the site turned up indentations in the ground and a
\nlevel of radiation in the area that was significantly higher than
\nordinary. More witnesses at the same base reported the U.F.O. again on
\nsubsequent nights. The deputy base commander reported that the aircraft
\naimed light beams into the most highly sensitive area of the base \u2014 a
\nclear security breach. <\/p>\n
On March 30 and 31, 1993, there was a wave of U.F.O. sightings over
\nBritain. One witness described a triangular-shaped craft that flew
\nslowly over an air force base before accelerating away to the horizon
\nin an instant, many times faster than a jet. The British military
\nreported, \u201cThere would seem to be some evidence on this occasion that
\nan unidentified object (or objects) of unknown origin was operating
\nover the U.K.\u201d <\/p>\n
On April 23, 2007, a commercial airline pilot and some of his
\npassengers reported a huge cigar-shaped U.F.O. \u2014 the pilot estimated it
\nto be a mile wide \u2014 near the Channel Islands. At the time, air traffic
\ncontrollers reported to the pilot that radar picked up something, but
\nthat it was \u201cunknown traffic.\u201d<\/p>\n
In addition, there have been several incidents of near misses
\nbetween U.F.O.s and known aircraft \u2014 enough to prompt the Ministry of
\nDefense and the British Civil Aviation Authority to advise pilots, if
\nthey encounter anything, \u201cnot to maneuver, other than to place the
\nobject astern, if possible.\u201d<\/p>\n
The United States is no less vulnerable than Britain and France to
\nthreats to security and air safety. The United States Air Force or the
\nNational Aeronautics and Space Administration should reopen
\ninvestigations of U.F.O. phenomena. It would not imply that the country
\nhas suddenly started believing in little green men. It would simply
\nrecognize the possibility that radar alone cannot always tell us what\u2019s
\nout there. <\/p>\n