Unidentified Flying Objects: Project "Grudge" (Technical Report No. 102-AC 49/15-100)

## INTRODUCTION

Perhaps the most bizarre post-war phenomenon was the sudden barrage of reports, in the summer of 1947, describing unidentified objects in the sky. The incident which evidently triggered the volley was the now-famous account by Kenneth Arnold, in which he claimed to have seen "nine peculiar-looking aircraft" without tails, which flew in a chain-like line and "served in and out of the high mountain peaks." The handling of this incident by the press led to the unfortunate but descriptive term "flying saucer," which caught the public imagination. From that time on, there has been a fairly steady stream of similar reports, including some of "flying saucers" seen prior to the Arnold incident, which presumably otherwise would have gone unreported. (It is pertinent, therefore, to speculate whether any of the incidents would have been reported if Mr. Arnold had not made his observation.) Possibly, of course, we deal here with an excellent example of mass hysteria. In the interests of the defense of the country, however, it would be highly inadvisable to ignore the accounts, even though the change be remote that they contain any thing inimical to the nation's welfare. To this end, the present investigator, as an astronomer, was asked to review the data, to eliminate the patently astronomical incidents and to indicate which others might have such an explanation.

## UNCLASSIFIED