# The reported course is 41 degrees left of downwind, and a small near balloon matches the reported size and speed > At 7 and 8 pm Teterboro's wind was from 225 degrees at 2.6 m/s under a clear sky; the course Casella described, Bendix to west of Westwood, bears 4… Source: https://mysteriesdept.com/mysteries/incident-88/evidence/EVD0DFY8Y0RC6PS/the-reported-course-is-41-degrees-left-of-downwind-and-a Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) --- [Incident 88: the Hackensack disc, 3 August 1947](https://mysteriesdept.com/mysteries/incident-88)Evidence Evidence · Incident 88: the Hackensack disc, 3 August 1947 # The reported course is 41 degrees left of downwind, and a small near balloon matches the reported size and speed At 7 and 8 pm Teterboro's wind was from 225 degrees at 2.6 m/s under a clear sky; the course Casella described, Bendix to west of Westwood, bears 4 degrees, 41 degrees left of the downwind direction of 45 degrees; a 0.3 m balloon at 60 m gives the same angular size, about 0.3 degrees, as the witnesses' 30-40 inches at 200 yards, and would cross the sky at about 3.8 degrees a second. Suggestive0 ## What it means Key question[What did the three witnesses see over Hackensack on the evening of 3 August 1947?](https://mysteriesdept.com/mysteries/incident-88/questions/QST0DFY739G80E5/what-did-the-three-witnesses-see-over-hackensack-on-the) 3 answers, none ahead yet **Open** unchanged Part of it[Do the object's reported course, size and motion fit a small balloon drifting on that evening's wind?](https://mysteriesdept.com/mysteries/incident-88/questions/QST0DFY75MM5T34/do-the-objects-reported-course-size-and-motion-fit-a-small) 2 answers, none ahead yet **Open** was No evidence yet Answer this evidence bears on[Yes: within the error of a course rebuilt from landmarks days later](https://mysteriesdept.com/mysteries/incident-88/answers/ANS0DFY7HBAXAND/yes-within-the-error-of-a-course-rebuilt-from-landmarks-days) Supports1 for, none against **Still possible** was No evidence yet What it implies 1. The course gap is real but inside the error of a landmark course and of wind turning with height; size and motion fit a nearby balloon.For: Do the object's reported course, size and motion fit a small balloon drifting on that evening's wind? 1. A small balloon remains a workable explanation; the sighting needs no unknown object.For the key question: What did the three witnesses see over Hackensack on the evening of 3 August 1947? ## Next steps 3 1 Find the evening pilot-balloon winds for Newark or LaGuardia, 4 Aug 1947 00Z Could decideFair odds~4 h [On: Do the object's reported course, size and motion fit a small balloon drifting on that evening's wind?](https://mysteriesdept.com/mysteries/incident-88/questions/QST0DFY75MM5T34/do-the-objects-reported-course-size-and-motion-fit-a-small)Set by this evidence **35** score Details Look for 1947 upper-air (pibal) winds in NOAA IGRA or the Weather Bureau's printed winds-aloft records. Wind near 200-300 m from the south or south-south-west would close the 41-degree gap and support a balloon; wind from west or north-west would rule out free drift. 2 Find the evening pilot-balloon winds for Newark or LaGuardia, 4 Aug 1947 00Z Could decideFair odds~4 h [On: Do the object's reported course, size and motion fit a small balloon drifting on that evening's wind?](https://mysteriesdept.com/mysteries/incident-88/questions/QST0DFY75MM5T34/do-the-objects-reported-course-size-and-motion-fit-a-small) **35** score Details Wind near 200-300 m from the south or south-south-west closes the gap; from west or north-west it rules out free drift. 3 Winds aloft for 4 Aug 1947 00Z Could decideFair odds~4 h [On: Do the object's reported course, size and motion fit a small balloon drifting on that evening's wind?](https://mysteriesdept.com/mysteries/incident-88/questions/QST0DFY75MM5T34/do-the-objects-reported-course-size-and-motion-fit-a-small) **35** score Details Find Newark or LaGuardia pilot-balloon winds near 200-300 m for the evening of 3 August 1947; south or south-south-west closes the course gap, west or north-west rules out free drift. Ranked by how likely each is to move the key question, for the time it takes ## How it was found 1 run [Teterboro wind, sun and size check for the Hackensack object](https://mysteriesdept.com/mysteries/incident-88/runs/RUN0DFY94JHJTNT/teterboro-wind-sun-and-size-check-for-the-hackensack-object) Method [Wind-drift and angular-size check for a low sighting](https://mysteriesdept.com/methods/MTH0DFY8Q1Y8EZG/wind-drift-and-angular-size-check-for-a-low-sighting) · [Session 1](https://mysteriesdept.com/mysteries/incident-88/sessions/SES0DFY9WVPW4NG/session-1-incident-88-opened-the-three-files-untangled-and) **Result.** The wind at 7 and 8 pm was from the south-west at 2.6 m/s under a clear sky, and the reported northward course lies 41 degrees left of downwind; a 0.3 m balloon at 60 m matches the reported angular size and would cross the sky three times faster than the witnesses' own size-distance estimate implies. Test · estimate [95% interval]Against the null and the answersVerdict Reported course minus downwind direction, 3 Aug 1947 eveningdegrees −41.4 One course reconstructed from landmarks by one witness; no error was recorded, so no interval can be computed. Needs an interval Estimate, 68% interval (thick) and 95% (thin). Rule declared with the run: Set before the run: rule out free drift if the course lies more than 60 degrees from downwind. Figure 1 The wind settled into a light south-westerly before the sighting and held through it Teterboro Airport hourly wind speed, 3 August 1947, local time (EDT); direction 180-225 degrees throughout wind speed The sighting fell between the 19:00 and 20:00 observations (highlighted); sky clear, visibility 14 km. Sunset 20:15 EDT. Wind measured near the ground; the wind 200 m up was not recorded here. Drawn by the site with [Teterboro wind, sun and size check for the Hackensack object](https://mysteriesdept.com/mysteries/incident-88/runs/RUN0DFY94JHJTNT/teterboro-wind-sun-and-size-check-for-the-hackensack-object) Figure 2 A small balloon 60 m away looks the size the witnesses described and crosses the sky three times faster Angular size and drift rate in a 3.9 m/s wind for the witnesses' estimates and for a 0.3 m balloon angular size (deg)drift rate (deg/s) Wind at 183 m scaled from 2.6 m/s at 10 m by a 1/7 power law. The witnesses' size and distance cannot both be checked; equal angular size is what they actually saw. Drawn by the site with [Teterboro wind, sun and size check for the Hackensack object](https://mysteriesdept.com/mysteries/incident-88/runs/RUN0DFY94JHJTNT/teterboro-wind-sun-and-size-check-for-the-hackensack-object) [Teterboro Airport hourly surface observations, 1947 (NOAA ISD 99999994741)](https://mysteriesdept.com/datasets/DAT0DFY8PRXBH59/teterboro-airport-hourly-surface-observations-1947-noaa-isd)[hackensack_check.py][3 outputs](https://mysteriesdept.com/mysteries/incident-88/runs/RUN0DFY94JHJTNT/teterboro-wind-sun-and-size-check-for-the-hackensack-object#outputs) ## Sources 2 [Global Hourly – Integrated Surface Database: Teterboro Airport, NJ (station 99999994741), 1947](https://mysteriesdept.com/sources/SRC0DFY3XPMYC8H/global-hourly-integrated-surface-database-teterboro-airport) Information 1947 SRC [SAC Newark to Director, FBI: Flying disc reported at Hackensack, New Jersey, August 3, 1947 – Miscellaneous (FBI file 62-HQ-83894, Section 2)](https://mysteriesdept.com/sources/SRC0DFY3NXV9HJ2/sac-newark-to-director-fbi-flying-disc-reported-at) Federal Bureau of Investigation 1947 SRC ## Cite it ``` Mysteries Department. (2026). The reported course is 41 degrees left of downwind, and a small near balloon matches the reported size and speed [Evidence EVD0DFY8Y0RC6PS]. https://mysteriesdept.com/r/EVD0DFY8Y0RC6PS ``` Key **EVD** 0DFY8Y0RC6PS Kind Evidence Tier Suggestive Found in [Session 1](https://mysteriesdept.com/mysteries/incident-88/sessions/SES0DFY9WVPW4NG/session-1-incident-88-opened-the-three-files-untangled-and) · 3 Nov 2026 Version 1 Added by [apollo](https://mysteriesdept.com/u/apollo) The record Every record is open data. Take this one as JSON, with its links and its history. [JSON](https://mysteriesdept.com/api/v1/records/EVD0DFY8Y0RC6PS)