Lightning flashed over Corona, New Mexico, and thunder rattled the thin windowpanes of the small shack where ranch foreman Mac Brazel slept. Brazel was used to summer thunderstorms, but he was suddenly brought wide awake by a loud explosion that set the dishes in the kitchen sink dancing. Sonofabitch, he thought to himself before sinking back to sleep, the sheep will be scattered halfway between hell and high water come dawn.

In the morning, Brazel rode out on horseback, accompanied by 7-year-old Timothy Proctor, to survey the damage. According to published accounts, Brazel and young Proctor stumbled across something unearthly -- a field of tattered debris 200-300 yards wide stretching some three-quarters of a mile in length. No rocket scientist, Brazel still realized he had something strange on his hands -- so strange that he decided to haul several pieces of it into Roswell, some 75 miles distant, a day or two later.

For all its lightness, the debris in Brazel's pickup bed seemed remarkably durable. Sheriff George Wilcox reportedly took one look at it and called the military at Roswell Army Air Field, then home to the world's only atomic-bomb wing. Two officers from the base eventually arrived and agreed to accompany Brazel back to the debris field.

As a consequence of their investigation, a press release unique in the history of the U.S. military appeared on the front page of the Roswell Daily Record for July 8, 1947. Authored by public-information officer Lt. Walter Haut and approved by base commander Col. William Blanchard, it admitted that the many rumors regarding UFOs"became a reality yesterday when the intelligence office of the 509th Bomb Group of the Eighth Air Force, Roswell Army Air Field, was fortunate enough to gain possession of a disc through the cooperation of one of the local ranchers and the sheriff's office of Chaves County."

Haut's noon press release circled the planet and was reprinted in papers as far away as Germany and England, where it was picked up by the prestigious London Times. UFOs were real! Media calls poured in to the Roswell Daily Record and the local radio station, which had first broken the news, demanding additional details.

Four hours later and some 600 miles to the east in Fort Worth, Texas, Brig. Gen. Roger Ramey, commander of the Eighth Air Force, held a press conference to answer reporters' questions. Spread on the general's office floor were lumps of a blackened, rubberlike material and crumpled pieces of what looked like a flimsy tinfoil kite. Ramey posed for pictures, kneeling on his carpet with the material, as did Maj. Jesse Marcel, flown in from Roswell for the occasion. Alas, allowed the general, the Roswell incident was a simple case of mistaken identity; in reality, the so-called recovered flying disc was nothing more than a weather balloon with an attached radar reflector.

"Unfortunately, the media bought the Air Force cover-up hook, line, and sinker," asserts Stanton Friedman, a nuclear physicist and co-author with aviation writer Don Berliner of Crash at Corona, one of three books written about Roswell. "The weather-balloon story went in the next morning's papers, the phone calls dropped off dramatically, and any chance of an immediate follow-up was effectively squelched."

Ramey's impromptu press conference marks the beginning of what Friedman refers to as a " 'Cosmic Watergate,' the ongoing cover-up of the government's knowledge about extraterrestrial UFOs and their terrestrial activities." By contrast, says Friedman, the actual Watergate snafu and cover-up pales in significance. In fact, if Friedman and his cohorts within the UFO community are correct, military involvement in the recovery of a crashed flying saucer would rank as the most well-kept and explosive secret in world history.

Of course, not all students of the subject see it that way. "You have to put Roswell in a certain context," cautions Curtis Peebles, an aerospace historian whose treatment of UFOs as an evolving belief system in Watch the Skies! was just published by the Smithsonian Institution. "And the relevant context is the role of government and its relationship to the governed. Americans have always been suspicious, if not actively contemptuous, of their government. On the other hand, forget what the government says and look at what it does. Is there any evidence in the historical record that the Air Force or government behaved as if it actually owned a flying saucer presumably thousands of years in advance of anything on either the Soviet or U.S. side? If there is, I didn't find it."

Regardless of its ultimate reality, however, Roswell symbolizes the difficulties and frustrations Friedman and fellow UFOlogists have encountered in prying loose what the government does or does not know about UFOs. Memories fade, documents get lost or misplaced, witnesses die, and others refuse to speak up, either out of fear of ridicule or, according to Friedman, because of secrecy oaths. Despite a trail that lay cold for more than 30 years, UFOlogists still consider Roswell one of the most convincing UFO cases on record. In 1978, for example, Friedman personally interviewed Maj. Jesse Marcel shortly before his death. "He still didn't know what the material was," says Friedman, "except that it was like nothing he had ever seen before and certainly wasn't from any weather balloon." According to what Marcel reportedly told Friedman, in fact, the featherlight material couldn't be dented by a sledgehammer or burned by a blowtorch.

Yet getting the Air Force itself to say anything about Roswell in particular or UFOs in general can be an exercise in futility. Officials are either bureaucratically vague or maddeningly abrupt. Maj. David Thurston, a Pentagon spokesperson for the Air Force Office of Public Affairs, could only refer inquiries to the Air Force Historical Research Center in Montgomery, Alabama, where unit histories are kept on microfilm for public review. But a spokesperson there said they had no "investigative material"and suggested checking the National Archives for files from Project Blue Book, the Air Force's public UFO investigative agency from the late 1940s until its closure in December of 1969.

Indeed, the dismissive nature with which U.S. officials treated Blue Book research seemed to indicate they were unimpressed; on that point, believers and skeptics alike agree. But according to Friedman and colleagues, that demeanor, and Blue Book itself, was a ruse. Far from the eyes of Blue Book patsies, in top-secret meetings of upper-echelon intelligence officers from military and civilian agencies alike, UFOs -- including real crashed saucers and the mangled bodies of aliens -- were the subject of endless study and debate. What's more, claims Friedman, proof of this UFO reality can be found in the classified files of government vaults.

With all this documentation, Friedman might have had a field day. Unfortunately, researchers had no mechanism for forcing classified documents to the surface until 1966, when Congress passed the Freedom of Information Act (FOIA). The FOIA was later amended in the last year of the Nixon administration (1974) to include the Privacy Act. Now individuals could view their own files, and some UFOlogists -- Friedman included -- were surprised to find that their personal UFO activities had resulted ingovernment dossiers.

Be that as it may, UFOlogists saw the FOIA as a means to an end, and beginning in the 1970s, their requests and lawsuits started pouring in. Attorneys for the Connecticut-based Citizens Against UFO Secrecy (CAUS) and other UFO activists eventually unleashed a flood tide of previously classified UFO documents.

In many cases, notes Barry Greenwood, director of research for CAUS and co-author with Lawrence Fawcett of The Government UFO Cover-up, most agencies at first denied they had any such documents in their files."A case in point is the CIA," says Greenwood, "which assured us that its interest and involvement in UFOs ended in 1953. After a lengthy lawsuit, the CIA ultimately released more than a thousand pages of documents. To date, we've acquired more than 10,000 documents pertaining to UFOs, the overwhelming majority of which were from the CIA, FBI, Air Force, and various other military agencies. It's safe to say there are probably many more we haven't seen."

As might be expected, the UFO paper trail is a mixed bag. Many of the documents released are simple sighting reports logged well after the demise of Blue Book. Others are more tantalizing. A document released by the North American Aerospace Defense Command (NORAD) revealed that several sensitive military bases scattered from Maine to Montana were temporarily put on alert status following a series of sightings in October and November of 1975. An Air Force Office of Special Intelligence document reported a landed light seen near Kirtland Air Force Base, Albuquerque, New Mexico, on the night of August 8, 1980.

Another warm and still-smoking gun, according to Greenwood, is the so-called Bolender memo -- named after its author, Brig. Gen. C. H. Bolender, then U.S. Air Force deputy director of development. Dated October 20, 1969, it expressly states that "reports of unidentified flying objects which could affect national security . . . are not part of the Blue Book system." Says Greenwood, "I take that to mean that Blue Book was little more than an exercise in public relations. The really significant reports went somewhere else. Where did they go? That's what we would like to know."

Of course there are objections to such a literal interpretation. "As I understand the context in which it was written," says Philip Klass, a former senior editor with Aviation Week and Space Technology and author of UFOs: The Public Deceived, "the Bolender memo tried to address the problem of what would happen with UFO reports of any sort following the closure of Project Blue Book. Bolender was simply saying that other channels for such reports, be they incoming Soviet missiles or whatever, already existed."

Greenwood counters that the original memo speaks for itself, adding that "the interesting thing is that sixteen referenced attachments are presently reported as missing from Air Force files."

Missing files are one problem. Files known to exist but kept under wraps, notes Greenwood, are another. To make his point, he cites a case involving the ultrasecret National Security Agency, or NSA, an acronym often assumed by insiders to mean "Never Say Anything." Using cross references found in CIA and other intelligence-agency papers, CAUS attorneys filed for the release of all NSA documents pertaining to the UFO phenomenon. After initial denials, the NSA admitted to the existence of some 160 such documents but resisted their release on the grounds of national security.

Federal District Judge Gerhard Gessell upheld the NSA's request for suppression following a review (judge's chambers only) of the agency's classified 21-page In Camera petition. "Two years later," Greenwood says, "we finally got a copy of the NSA In Camera affidavit. Of 582 lines, 412, or approximately 75 percent, were completely blacked out. The government can't have it both ways. Either UFOs affect national security or they don't."

The NSA's blockage of the CAUS suit only highlights the shortcomings of the Freedom of Information Act, according to Friedman. "The American public operates under the illusion that the FOIA is some sort of magical key that will unlock all of the government's secret vaults," he says, "that all you have to do is ask. They also seem to think everything is in one big computer file somewhere deep in the bowels of the Pentagon, when nothing could be farther from the truth. Secrecy thrives on compartmentalization."

In recent years, UFOlogists have found an unusual ally in the person of Steven Aftergood, an electrical engineer who directs the Project on Government and Secrecy for the Washington, D.C.-based Federation of American Scientists, where most members wouldn't ordinarily give UFOs the time of day. "Our problem," says Aftergood, "is with government secrecy on principle, because it widens the gap between citizens and government, making it that much more difficult to participate in the democratic process. It's also antithetical to peer review and cross-fertilization, two natural processes conducive to the growth of both science and technology. Bureaucratic secrecy is also prohibitively expensive."

Aftergood cites some daunting statistics in his favor. Despite campaign promises by a succession of Democratic and Republican presidential administrations to make government files more publicly accessible, more than 300 million documents compiled prior to 1960 in the National Archives alone still await declassification. Aftergood also points to a 1990 Department of Defense study, which estimated the cost of protecting industrial -- not military -- secrets at almost $14 billion a year. "That's a budget about the size of NASA's," he says, adding that "the numbers were ludicrous enough during the Cold War, but now that the Cold War is supposedly over, they're even more ludicrous."

Could the Air Force and other government agencies have their own hidden agenda for maintaining the reputed Cosmic Watergate? Yes, according to some pundits who say UFOs may be our own advanced super-top-secret aerial platforms, not extraterrestrial vehicles from on high. Something of the sort could be occurring at the supersecret Groom Lake test facility in Nevada, part of the immense Nellis Air Force Base gunnery range north of Las Vegas. Aviation buffs believe the Groom Lake runway, one of the world's longest, could be home to the much-rumored Aurora, reputed to be a hypersonic Mach-8 spy plane and a replacement for the recently retired SR-71 Blackbird.

In fact, the Air Force routinely denies the existence of Aurora. And with Blue Book a closed chapter, it no longer has to hold press conferences to answer reporters' questions about UFOs. From the government's perspective,the current confusion between terrestrial technology and extraterrestrial UFOs could be a marriage of both coincidence and convenience. The Air Force doesn't seem to be taking chances. On September 30 of last year, it initiated procedures to seize another 3,900 acres adjoining Groom Lake, effectively sealing off two public viewing sites of a base it refuses to admit exists.

By perpetuating such disinformation -- if that is, in fact, what's happening -- the Air Force might be using a page torn from the Soviet Union's Cold War playbook. James Oberg, a senior space engineer and author of Red Star in Orbit, a critical analysis of the Soviet space program, has long argued that Soviet officials remained publicly mum about widely reported Russian UFOs in the 1970s and 1980s because such reports masked military operations conducted at the supersecret Plesetsk Cosmodrome. "Could a similar scenario occur in this country? It's conceivable," concedes Oberg. "On the otherhand, should our own government take an interest in UFO reports, especially those that may reflect missile or space technology from around the world? Sure. I'd be dismayed if we didn't. But does it follow that alien-acquired technology recovered at Roswell is driving our own space technology program? I don't see any outstanding evidence for it."

Friedman's counterargument is not so much a technological as a political one. "Governments and nations demand allegiance in order to survive," he says. "They don't want us thinking in global terms, as citizens of a planet as opposed to a particular political entity, because that would threaten their very existence. The impact on our collective social, economic, and religious structures of admitting that we have been contacted by another intelligent life form would be enormous if not literally catastrophic to the political powers that be."