PROJECT 10073 RECORD CARD I. DATE 2. LOCATION .'i~ (' 12. CONCtUSIONS TYPE O F OBSERVAi!ON . S. P H OTOS )!X G round Vi suo I 0 Ai,. Visual 0 GroundRodor 0 Airlnt~trcept Rod e r 1. LEI'ICTH o:: :aSERV A'riON a. NUMBER Of OBJ~CTS 9. COU?:iE 11. COMMENTS Was Balloon P rol,obly Balloon Possihly Balloon Wn s Aircr aft P rob obi y A i rcroh Po ui bl y Ai rc:roh Wo, Astronomic: ol _ P robably Ast ronomi col Po$'iibly Astronomical l1suffioiont Data for Evaluation BOLIDE OF 1904 JULY 1~, A.M.S. No. 2384 BY CHARLES P. OLIVIER Narllerllt, PettNsy/tNJNUJ Over sixty visual observations of an unusually bright bolide, sighted over British Columbia on July 19, 1964, 0 :44 p.m. P.S.T ., have been analysed to determine the approximate parabolic path of the object. Plus de soixante observations visuelles d'un bolide particuli~rement brillant appe~u dans le ciel de Ia Colombie Britannique le 19 juillet 1064 a\ 9 :44p.m. heure normale du Padfique, ont ftf analysees pour d6terminer Ia trajectoire parabolique approximative de l'objet. ON July 19, 1964, at 9:44p.m. P.S.T., an unusually bril1iant bolide was sighted over British Columbia and, moving in a general south-easterly direction, ended over Washington. Mr. P. F. Brogan, regional director for the American Meteor Society, began collecting reports at once from residents in the states of Oregon and Washington. Eventually these were sent to the writer, who belatedly attempted to calculate the path. However, it became evident that sighting reports from Canada would vastly assist in the solution, hence Dr. P. M. Millman of the Meteor Centre, National Research Council, Ottawa, was asked for assistance. He promptly supplied over 30 Canadian reports as well as a dra wing of a preliminary projected path, derived by Prof. W. F. Slawson, University of British Columbia, Canada, from observations he had collected. Three reports were received from the U.S. Air Force, so that over 60 observa- tion's with varying degrees of accuracy were available. The stations were plotted on a specially prepared map of the region, and azimuth lines were drawn for the directions in which the bolide was and last observed from each station. As always there were great divergencies but fortunately the Canadian observer at longitude 122 59' W., latitude 49 13' N., saw it begin at 11 Ursae Majoris and cross over ~ Aquilae actually it went much further. This observation gave funda- mental points on the path and a very fine projected path since it passed almost through his zenith. Several other Canadians saw it near their zeniths and could tell on which side it passed. These observations con- firmed the above projected path. The sub-end point was based mostly on American reports and a large proportion of these gave estimated R .A.S.C . joua., Vol. 59, No. 6 Cluzrles P. Olmer altitudes. One Canadian gave the path plotted among the stars, but his calculated altitudes could not be reconciled with other observations used to define the path. To derive the heights of the beginning and end points the path was very difficult. First, it is well established that most casual observers greatly:. over-estimate altitudes if these are more than 15 or 2() In this case some very distant observers gave altitudes of 30 to 45 which would give unreasonable heights and contradict nearer and ap- parently more accurate reports. The heights finally adopted are the result of a series of approximations, too lengthy to describe in detail. A vertical plot was made of many intermediate points as well as the beginning and end points. (One inter- point was almost certainly taken for the end point by many observers since a great outburst of brilliancy took place there.) A line then drawn which conformed as well as possible to these various This choice is confirmed by the statement from many observers that the path was almost or exactly horizontal. The adopted heights of beginning, end, and the intermediate burst point, are given in the table. On account of the great length of path, an error of a few kilometres will have little effect on the radiant point and the orbit. This latter can be considered to have a greater accuracy than the heights. The opinion of most observers was that the colour was either blue, white or green, or a combination of these colours and blue-green is probably correct. The bolide was very brilliant with the zenithal magnitude at least -12; even distant observers the brightness is given as that of the quarter moon. In deriving the duration of flight, estimates were omitted of those observers who stated that they saw only part of the path. In addition, 00 seconds was left out as being much too discordant; indeed it may conceivably refer to the train, though statements as to the latter are few and contradictory and most observers apparently saw none. The duration of from 3.5 to 5 seconds given by many observers indicates that they saw only part of the path or underestimated duration, but these values were included. There were seve.ral bursts; one observer states there were six. It is unfortunate that no report was received from the region near the end point, but that part of Washington is sparsely populated. If our end height is nearly correct, any chance of recovering meteorites is small d espite the bolide's unusual brightness. The parabolic orbit which follows shows direct motion and an inclination of 8, which is reasonable if the bolide came from the asteroidal zone . Sidereal time a t end Began over BolUle of 196~ July 19, A.J.l.S. No. SS8~ Burst over Ended over Projected path Observed velocity Radiant uncorrected Curvature correcnon Zenith correction Corrected radiant Parabolic orbit 8.0 % 4.2 sec. (32 observations used) 62 % 32 km./sec. (very uncertain) This bolide has been assigned No. 2384 by the American Meteo The writer expresses his most sincere thanks to r. 1 m_an or sa generously lending the thirty-odd Canadian reports; a?y solut1on woul have been very uncertain without these. We also wtsh to thank ~1t Brogan, whose personal work is responsible for ~ost of the Amenca: Air Force for their co-operation. Lastly, we than. repo s, th more than 6() individuals who made the observati~ns and t~k e tim to report; without such co-operation the calculation of orb1ts would b impossible. DEPARVt\~NT OF THE AIR FORCE ST A~:= t ~ESSAGE sqANCll UNCL~SSlFIED ACTION: NIN- 7 IrWO : XOP-1~ XOPX-5, SAF-OS- 3 , DIA-15 (32) DZ RUWHK? ll 20/2047Z F~ POADS AJAIR AFS OREGON TO RUI,,GALVAIR DEFENSS C O ND ENT AFB COLORADO RUWHBH/25 ~I R DIV MCCHO~O AF3 WASHI~JGTON PAGE 1 of 2 RUCJSQ/~!~ 7ECHNICAL I~T lGENCE CNETER WRIGHT PATTERSON AF8 OHIO RUEAH~/HEACQUARTERS USAF ~ASHINGTON RUEAH~/SECR!TARY OF THE AI~ FORCE WASHINGTON UNCLAS POODC- I 20- G- 5 FOR AFC!N- HQ USAF; SAF'OI -SECRETARY OF THE AIR FORCE. UFOB R~POrtT. THE fOLLOWI NG UFOS I S FORWARDED IN ACCORDANCE WITH AFR TH~N ROCKET 2 It PENCIL. AND GRZC:N WITH \tlHITE LIGHT BETWEE:N. 5. NOT/ APPLICABLE. 6. APPEARED TO BE AIRCRAFT THE~J ASSUMiD APPEARANCE 0~ A ROCKET~ lt-ICvMING . .-. r1iESSAGE DEPARTMENT OF THE AIR FORCE STAFF MeSSAGE G~ANCH SUSPRCT~D DU?LICATE CHQA332Z.C~Jt\430 PP rtU~AHQ ZNR Zrrl-1 ?P rtUCDSQ RU~AHQ RUWGALS ~U~HBH P? RUCDSQ RUiArlQ RUWGALE ~U~H3H D~ RUWHaME 2 23/0331Z F~ 635 RADAR SQ CONDON AFS ORE TO rtUCDSQ/AFSC WRIGHT PATTSRSON AFB OHIO INFO rtUEAHQ/S,;~ .I.~SHDC rtU2AHQ/HQ CO~D USAF WASHDC RU '.~GALE/ ADC EL'-l T AF B COLO RUWriSH/WT AIR DIV MCCHORD AFB WASH FO~ AFSC, FTD. INFO: SAFOI, USAF, AFC"LN. SUBJE:CT CUFO) T:iiS ~L.::.3~.~G;:: IN T'.~2LVE PARTS .. PART I. SPHE~IC/~L 2 .. SIZE Or D:1~ '\T ~NCOMING . ~JtESSAGE . DEPA~HMENT OF THE AIR FORCE STAFF MESSAGE GRANCH AR~ 1; LS-..JGTH, 3 . INTENSE \vHITC: LIGHT, 4 . ONE, 5 , N/A 6 , NONE, 7, TRAILING EXHAUST, SMALLER WHITE SPOTS TRAILING BEHIND SEEN BY MRS r:iC.ELLIGOTT. TRAIL NOT OBSERVED 'BY MR t1CELLOGOTT. 8 . NONE 9. EXCEPT IO~AL B~IG~TN2SS, MOST UNUSAL FEATURE. PART II. 1. HAPPENED TO LOOK OUT F~ONT PICTURE WINDOW. 2 . APPOXIMATELY TEN (10) DEGREES ABOVE dO~rz::~ ~ND TKR::2 FORTY (340) DEGRES AZIMUTH 3. SAME ELEVA TION AND T~Rzr FIFTY FIVE C355) DEGREES AZIMUTH 4. ST~AIGHT FLIGHT ~0 M~\~2UVE~S, FLAT TR~JECIC~Y. 5 . DISAPPEARED BEHIND HILLSIDE TO \\lOrtTH. PART III. 1. GROUNJ 'I ISUAL 2. NONE 3, N/A PART IVc. 1-> 0555Z 20 J ULY 195~ 2 . NIGHT. Pri27 V. TWENTY FOUR (24) MILES NNE OF.CONDO~ I ONE ORE FARMER RZLiri3LS 03S.!:RVER SC:RVED IN ARivtY AIR CORPS. 194 2-1945., CAPT PILOT AGE 39, CWIFE> RELIABLE OdSERVEa PA~T VII. NO WINO, CLEAR, BEFORE MOON RISE SURFACE WINDS CALM. oasERVER. WINDS ALOFT 5,000 FT 280 DEGREES AT 10 KNOTS 10,000 FT, 280 DEGREES AT 18 KNOTS. UNLIMITED . R. UNLIMITED. 5 . NONE 6 . NONE 7. NOT AVAILAdL~ PAR! VIII. NONE. PART IX. NONE KNOWN. PART XI. I NTELLIGENCE OFFICER 6360AC- OP CONDUCTED ON THE SPOT SURVEY. OBSERVER CMR ) . BELIEVES IT CJ~LD HAVE aESN A FIREBALL BUT FLAT TRAJ~CTORY OF TRAVEL ~lADE lii M WONJ . FROM THE ANALYSIS OF OBSERVER' S DISCRIPTION A~IO I~ TLLIGENC E OFFICER'S I~SPECTION OF THE LOC~TION OF SIG~T!NG, 03JECT SEEN IS BELIEVED TO dE A METORITE. FLAT TRAJECT9RY COULD H.~Vt. B!::::N AN OPTICAL ILLUSIOn TO 03SERVER SINCE HE SA\v IT FO~ SUC,{ A tsRIC:F PE:RIOD OF T H'lE. PART XI I . rJONEo NOTE: Original transmiasion not receive d in sri!B. DOLlDIZ OF 10G4: J ULY \ 0 , 1\.l\l.S. No. 2384 llY CH:\Hl.ES r . O r.!VlER S nrbcrlh , I'cntJIJ!mnia An!HI<M.:T (Jver s i:o<t)' vi:'U\\1 observatioll~ of :11\ UIIUS II Ii\y hril{ht b~)\it\e, !li~htcd 0\tCr nritis h C olu111bia on July Hl, 1!1f,4, !J:l4 p.rn. P.S.T., lt.IVt' twcn a nalyst!<.! to tlelcrnline the appru .<im.tte p.:uabolic f'lr\th of the o\Jjel't. l 'lu~ de 5Ciixante oi1~ervations vi5ucllt!!> cl' u n bolide p;1r ticulil:r\!rnent bri\lant apper\ U d.lll!> le cicl d" Ia C .... \o mhiP llritanuiquc: lc IU juillet lH6-4 :\ !1:-t-l p.nt. h<>urt-uormnle tlu i'acifique. ont ~tt! a n.1ly es pour d(terminer l.l t r,1jcctoin:: pamuoliq u~ appro:<i11\.\tive d e l'ohjet . 0::-: July HI, H1b-nt 9: I~ p.m. P.S.T., Rll unu~ually br!lli<.tn t bolide w.ts s ighted o'er i)::t.~h Columbia a11d, moving i11 C\ ~Cilf'rRI soullt-eastcrly direction, end~ri ,.,.,~r \Vashin ton. ;\fr. 1'. F. Brogan, regional dirt!Ctor for the Atncrir<~ :.f~tcor Soriely, b ct'clr\ collcctin~ rc!ports :.Lt once from residents in t h e 5~J.t of Oregon and \V,1shington. Evcntuallr these were sC'nt to the ,,,-:~r, who iH:b.U:dly attcn1ptcd lo alculate th~ p .1th. Howev':!r, it b~c. .. "TTc evident that si~hting n :ports frorn Cauatla \VOuld vastly <1s~ist h r.~c solution, hence I )r. r. l\ L i\[illman of the l\fett:or Centre, J\al: 1n! Rt:scan;h Co11ncil, Ottawa, was asked for assistance. He promptly su;Jplied ovt!r 30 CC~nadian rcportR a~ well as a drRwing o f a preliminary p r ~)cded path, dcri vt!d b y Prof. \V. F. Slawson, Universit y of British Cvl'-li:'lbia, CaoadR, frc..m ol,servations he h a d coll~t.:ted. Three rf'ports were r~eived from the U.S. Air Force, so that over GO ob::;erva- tiru\s with var)ing degrees o f accuracy we r e available. Tltc stations were plotted o n a specially prepared m<.tp of the region, and azimuth lin~s were drnwn fo r the directions in w hic h the b oliJe was firs t and last observed from each station. As a \ ways there ''ere g reat divergencies but fortunately the Canadian obR~rver at longitude 122 59' \ V., latitude 4:9, 13' N ., sRw i t begin at a. IJ rsae ~l<\joris and c ross over o Aquilae acn aily it went much further. This observation gave funda - mental points o n the path and a very fine projected path ~ince it pa~ed almost throu~h his 7.enith. Several other Cunadians saw il ncar their .::eniths and could tell on which side it passed. These ooservations con rmed the abo"~ project(..'<.i pl1lh. The ~mh-end p oint '\\ l\S hast!d mostly o n Amt:ric<tn r eports and a l.u!;e proportion o f these gave estintated R.A.S.C. JouR., Vol. 50, ~o. G Charles P. Olivier ...t:'it ~tics. One Can:1di:ln gnvc the path ploth:d among the stars, but his c;.t<..ti !t:d :tltitucic~ could not be reconciled \rith CJth~.r oh'lt-rn.1tious u::t-d to<.!.: .. 7~-: the pi.tth. To derive the heights of th~: beginning aud u~t.l p(lint!: of th~.: pa~h was \'cry difficult. First, it is w<II <:oilahlishcd that mo;;t c.~ ... , . tl OU!:>~rv~rs ~>r<:at1v ov~.:r-~.~timaiC' .tltitudls if lhlH: . tr~.uh.m.: tit~''' 1!, 01 .:tl''. In this u:;c s01:H.: \t'.) dt-.1.1111 llU:,~t\trs gave c.dtitudu: of 0U" tJ 1:)" '' hich \\ode! giv<: llPflo~''"'!'ll heights :l11<.l contradict nearer and ap- par\!!ltly more accur.tlc eJJ>Jlt.- The hc.:ights finally adopted arc the result of a series of approximations, too !eng-thy to describe in detail. ,;\ vcrtic:1l plot was made of many intcrm~diatc points as well as the Lcginning ~nd end points. (One intcr- dbte point \'::!s a lmost certainly taken for the end point by !~ .llly observer::; since a grca t out burst of IJrill i:uwy took place flwrl'.) A I; 11c was theu dr:J.wn which confurHJttl a!i wdl :t!:-pus!:>iblc t <' tlh'.;c; \a icu;; points. This choice i s confir lllctl b y th<: s t alt'IIICJll from m.111y o!J~cl v~;1 s t hJ t the p:: th \\':lS almost or exactly horizon tal. The adopted hc:itih ts of bq;inning, end, and the intermedi:J.tc burst point, a re given in the table. On <lccount of the gre:ll length of path, an error of a few kilometres will h:n-e little effect on the radiant point and the orbit. This btter can be considcrl!d to haYe a grea rcr accuracy than the heights. The opinion of most ob~crYcrs was that the colour was either blue, \\'hite or green, or a l'Ot~1bin:nio:1 of t ht:s~. colours and blue-green is probably correct. The bolide \\':.iS \'Cry Lrilli;mt with the zenithal magnitude at least -12; e\'en di..;t:tnt obst'rvE-rs the brightness is given as that of the quarter moon. ln deriving t he duration of flight, estimate-s were omitted of those