OCR recovered text quality varies — view PDF for accurate reading. \ i | | | ‘ i | | 4 | |= 15. BRIEF SUMMARY OF SIGHTING § | i I i | | | 1. 3. DATE-TIME GROUP A PROJECT 10073 RECORD CARD LOCATION DATE Hoxkaido, TYPE OF OBSERYATION o_Ground- Visual 19 February 1958 Local GAT _19/0059% O Air Visual Japan 0 Air-lntercept Radar | | iW 12. CONCLUSIONS Wos Balloon Probably Bolloon Possibly Belicon ooo X Sround-Roder Waa Alresalt Possibly Aircroft — p [1 oT 0s Sn oo . — — é. 50 u RC E oo OYss suatreh ol Sek MH i 7. LENGTH OF OBSERVATION Military 3. NUMBER OF OBJECTS ‘2 one hours dagar report from Sea of Japan area, dleturn daveloped rapidly to 2 dense cloud that expanded to cover an arsa 1poroximately 695 miles long and rose (rom an altitude of 3,000 ft to 48, VOUft, Return similar to weather return axcent for speedof development, “ive aircraft in area all turned towarq raturn and proceeded to the general Hel=. ll Area, Heturn resembled explosion of | large munitions ship exploding, | ATIC FORM 117 (FEV 18 SEP 52) Was Astronomical Prabebly Astronomical Possibly Astronomical 2. COURSE _Explosis Ihsolficiont Doto for Evoluation nk no wn Stationary | COMMENTS Rapid devalopment 2nd a/c rule out weather ophonomena equipment malfunction, EL and Probobly Aircraft nm ow ded A = AC | 1 Lal txplosion| possible cause correlated with IR 1880-08 as explosion. by fishermen, Also seismic from Matsushirn, Oosearva=dy detec + tion of nuclear explosion reports