UAP Reported at Sandia Base, 1948-1950

Read from the scan by GLM-OCR; expect the odd misread word.

10:00 - 12:00 A.M. on July 26th. At this conference it became apparent that Dr. Crozier was inclined to attribute the unusually large copper fragments collected on July 25 at 10:00 A.M. ("which because of their size could not have been blown very far by surface winds") to particles blown off the roof or out of the gutters of the Assaying Building on the Campus. In answer to a question from the writer, Dr. Crozier replied that he would consider this possibility ruled out if copper particles showed up in collections made in the open country at considerable distances from the Campus. It was therefore recommended that such collections be made and Dr. Crozier and Mr. Seely rigged up a storage battery combination and small D.C. motor driven impactment collector which were loaded into the O.S.I. staff car and driven out through San Antonio, Carthage, and Bingham, New Mexico (this route passing, in Mr. Taft's opinion, through the region where particles from the fireball of July 24th would most probably have been carried by the very light winds prevailing in the region since the incident.) Four of the collections made on this trip were examined on the evening of July 26th by Mr. Ben Seely and all were found to contain copper particles indistinguishable from those collected in Socorro at about the same time.

(3) Full details on the methods of collection employed by Dr. Grozier and Mr. Seely and on later examinations of the dust particles collected after the green fireballs of both July 24th and August 6th are given in Dr. Grozier's report [R/D - tw, 8-10-49] copies of which are hereto appended. Dr. Grozier's tentative conclusion from study of the collections made, not only in connection with the incident of July 24th, but also that of August 6th, is that "the results of the present investigation should be regarded as negative or inconclusive." From analysis of his report [R/D - tw, 8-10-49] and from several phone conversations with Dr. Grozier, it is the writers belief that Dr. Grozier was led to the above conclusion by the following facts listed below in decreasing order of importance, and accompanied by critical comments:

(3.1) The discovery by tests made on or about August 1 of " a few copper indications" in dust collected at Socorro on July 14, 1949, i.e. ten days before the green fireball incident of July 24th. (Dr. Crozier has informed the writer that the collection of July 14th was carefully wrapped up and could not have become contaminated by copped dust which blew in through the open windows of the R.D. & D. Building at Socorro after the incident of July 24th. However, there remains the possibility that an unobserved or unreported green fireball occurring in the Socorro neighborhood shortly before July 14th put down the copper dust found in the July 14th collection. To one familiar with the almost uninhabited country around Socorro and the fact that green fireballs as bright as the half moon occurring at times as favorable for observation as 7:30 8:30 P.M. have gone almost unreported, it seems quite likely that a green fireball that fell after midnight or during the daytime or while most of the sky was overcast might go entirely unreported.)

(3.2) The discrepancy between the computed and observed rates of descent of very fine copper particles. (As Dr. Crozier notes, such discrepancies are understandable "if some downward motion had taken place in part of the air involved." Precisely such downward motion occurred in the air near the real paths of the fireballs of July 24th and August 6th for these falls were nearly vertical. Furthermore the best observations of the endpoints of these fireballs place that of July 24th at a high of 18-12 miles and that of August 6th at 5-6 miles. The downward directed ballistic head wave therefore could very easily have carried Dr. Crozier's 145 hour particles to within 10,000 feet of the earth at