Visual Observations at Bentwaters, 2255

An Opinion by Martin Shough

The 1956 Blue Book evaluation of all visual observations reported from Bentwaters and Lakenheath was: "astronomical". This included the star-like object seen, according to IR-1-56, from Bentwaters Control Tower from 2120-2220Z during the earlier radar trackings. The Control Tower Chief on this shift was S/Sgt. Lawrence Wright, who gave a very good description of the planet Mars rising in the SE, periodically dimmed by patches of dissolving cirrus:

Sgt Wright indicated that his attention was first called to the object by its position, size and unusual color. He was also aware that the Bentwaters GCA was tracking Unidentified Flying Objects by radar at this time. Sgt Wright described the UFOB as spherical and the size of a pin-head held at arms length. He sighted only one object which was described as amber color when first observed later changing to bluish-white. . . . He indicated that the object was first observed at about 10° elevation toward the south east. The object was in sight for approximately one hour during which time it intermittently disappeared and reappeared. At the time of the object's disappearance, it was located approximately 40° above the horizon in south south-easterly direction.

Mars had risen shortly before 2100 and at 2120 was about 4° above the horizon at 108°, or just south of East. Sgt. Wright's description exaggerates the degree of lateral movement. By 2200 Mars had risen to about 13° and moved further to the SE at 120° azimuth. He also consistently overestimates the elevation angles by several hundred percent. This is a type of systematic perceptual error which is well-documented and in sense 'accurately reported' by Sgt. Wright, so we can be fairly confident in agreeing with Blue Book that this object was Mars.

The main interest of this episode is that during an hour of observation from the Control Tower at a time when GCA was reporting UFOs - a cluster of unexplained radar targets passing slowly NE overhead, and a fast target heading E-W overhead - Tower personnel were looking for UFOs and yet saw nothing but Mars. (Note: IR-1-56 appears to be in error in stating that radar observations began at 2130. Internal evidence suggests that '2130' should read '2100', thus explaining how Sgt. Wright could have been 'aware that Bentwaters GCA was tracking UFOs by radar' at 2120.)

Otherwise, Blue Book's evaluation of "astronomical" means specifically meteors of the Perseid shower, although the Project's astronomical consultant, Dr. Hynek, himself dissented from this conclusion in a file memo:

It seems highly unlikely, for instance, that the Perseid meteors could have been the cause of the sightings, especially in view of the statement of observers that shooting stars were exceptionally numerous that evening, thus implying that they were able to distinguish the two phenomena.

This relates to the preparing intelligence officer's statement in BOI-485, in response to the request for "Any other unusual activity or condition, meteorological, astronomical or otherwise, which might account for the sighting":

Ground observers report unusual amount of shooting stars in sky. Further state the objects seen were definitely not shooting stars as there were no trails behind as are usual with such a sighting.

However the statement appears to refer to other observations made by ground observers at Lakenheath (discussed elsewhere), and it is true that the 2255 Bentwaters visual is much easier to interpret as a meteor (qualitatively speaking) than the objects with more complex motions reported later. According to BOI-485:

At 2255Z, 13 Aug 56 Bentwaters GCA sighted object thirty miles east of the station travelling westerly at 2000-4000 mph. Object disappeared on scope two miles east of station and immediately appeared on scope three miles west of station where it dissappeared thirty miles west of station on scope. Tower pers at Bentwaters reported to GCA a bright light passed over the field east to west at teriffic speeds and at about 4000 feet alt. At same time pilot in aircraft at 4000 feet alt over Bentwaters reported a bright light streaked under his aircraft travelling east to west at teriffic speed. At this time Bentwaters GCA checked with RAF Station Lakenheath GCA to determine if unusual sightings were occurring.

Philip Klass advocated the Perseid hypothesis to explain the 2255 report, but did not mention the concurrent radar track [Klass 1974]. This concurrency is not only very clearly stated in BOI-485, it was also recalled independently by the Lakenheath RATCC. The reported E-W heading of radar target and E-W heading of the visual object are corroborative, and this heading is a significant datum in relation to the Perseid hypothesis, inasmuch as the position of the Perseid radiant makes it geometrically impossible for a Perseid meteor to be tracked on a straight diametric E-W heading (either by first-trip or multiple-trip) on Bentwaters radar (see Analysis of the Bentwaters Fast Radar Tracks).

It is possible, though, to try to separate the radar and visual reports from one another, and in Klass's account there is also an attempt to ascribe the ground- and air-visual observations to two quite distinct events. If valid, this interpretation would obviously somewhat reduce their significance. Thus we read that control tower personnel saw "a 'bright light' that seemed to pass over the field" and that "also" a C-47 pilot "reported seeing a bright light streak past". Klass then speaks of "the luminous objects", suggesting that "these visual UFOs" were different "meteors". This pluralisation removes the problem of the object's low altitude, since it would no longer be bracketed by simultaneous observation from above and below, and furthermore it conveys the idea of a meteor shower, but it is really a speculation superimposed on the report.

However, from this basis Klass interprets the report in BOI-485 that the pilot saw the light pass "under" his aircraft as meaning that "it appeared to him to be at a lower altitude", which in turn can be interpreted to mean that it was not necessarily seen at a depression angle but perhaps appeared to be some considerable lateral distance away and at no time either passed in front of the horizon or was lost to view beneath the wing or fuselage of the aircraft. Under these circumstances the pilot's report of lower altitude could be a subjective judgement of marginal difference in elevation, which could in turn be subject to significant error. This interpretation does not contradict the letter of the BOI-485/Perkins reports, at least, and clearly it would favour the meteor hypothesis.

The Perseids, although a rich shower numerically speaking with a frequency at maximum (two night before the events) of about 50 per hour, are small, swift particles yielding meteors of relatively small individual magnitude. But Klass invokes the precedent of a "giant meteor or fireball" reported as a UFO by a pilot near St. Louis, Missouri in June 1969 to illustrate that observers can be "grossly in error trying to estimate the altitude and distance of a fireball/meteor", which is quite true. But this fireball, as is typical in such cases, was witnessed and photographed by a great many observers from Illinois to Iowa, not by a handful of people in the same immediate vicinity - which is of course why we can be confident that it was a fireball.

The Perseids not only do not yield spectacular slow fireballs, but are at their faintest during the evening hours. It is after midnight that due to the motion of the earth they become brighter and reach maximum magnitude in the pre-dawn hours. Further, as indicated above, at the latitude of Bentwaters the Perseid radiant is never at any time due E, and at 2255 on August 13 its position is so far N as to raise a real inconsistency with the testimony.

The terrestrial bearing of the Perseid radiant at 2255 on August 13 is only about 35° E of true N, elevation approximately 30°, and it is clear that a meteor from this shower could not pass anywhere near the zenith and appear to be travelling E-W. An apparent E-W path would take the meteor on a trajectory only some 30° above the N horizon and thus not "over the field east to west" as reported in BOI-485.

This is not a strong argument when applied to the visual report alone, of course, human judgement not being amenable to the same simple inferences from time, distance and geometry as are possible with a radar system. It is true for example, as seen with Sgt. Wright's report above, that observers exhibit a strong tendency to overestimate visual angles, and the effect of such an exaggeration might be to bring the reported apparent path of the meteor closer to the zenith, which would go some way to repairing the inconsistency with the ground observations of a light that "passed over the field". But the same effect works in an opposite sense to increase the difficulty of interpreting the simultaneous report from the aircrew over Bentwaters: Neglecting the small increase in estimated terrestrial elevation due to the aircraft's 3/4 mile flight altitude, a meteor passing 30° above the aircraft's level wing (its apparent altitude exaggerated by overestimation of this angle) would seem unlikely to suggest a light travelling "under" the aircraft.* Further, since only line-of-sight meteors will become visible at or close to the actual position of the radiant, therefore showing relatively small angular displacement, and since the reports imply a relatively long visible path, the probable initial azimuth and elevation of the meteor would tend to be respectively N of 34° and higher than 30°. Alternatively, if the ground observers did see a Perseid on an apparent trajectory "over the field" - that is, travelling approximately NE-SW - but misjudged its heading by some 45°, reporting it as travelling E-W, then this meteor as viewed from the aircraft flying over Bentwaters would describe a rising apparent path taking it unambiguously over the top of the aircraft, and of course the aircrew too would be required to have misjudged its heading by 45° as well as misreporting its altitude as "under" the aircraft rather than "over".

Paul Fuller has offered the interesting suggestion that the aircrew saw a bright Perseid "reflected on ground mist, or low lying cloud, or water"; but it has to be said that the Perseids are not that spectacular, moreover there is no meteorological evidence either of detectable mist or of low cloud at this time; and even though the wide water of the Deben estuary is only a few miles SE of Bentwaters the geometry of the situation with the Perseid radiant in the NNE makes the explanation seem rather strained.

In summary the Perseid hypothesis is actually not very attractive, despite the coincidence of the events with one of the most prominent meteor showers of the year. Even though the shower was two days past its peak by the night of 13-14 August, this coincidence may seem too attractive to ignore. But if we say that the visual reports were due to a Perseid then we are trading one coincidence for another - the coincidence of a fast radar track which cannot be explained as due to a Perseid meteor.

The alternative is that one or both parties saw one-or-more chance meteors, unconnected with the Perseids, concurrent with Track C. Analysis of the Bentwaters Fast Radar Tracks explains why Track C could only have been generated (at an unfavourable wavelength, by multiple-trip echoes and on an unfavourable diametric zenithal trajectory) from a very large fireball indeed. It is noteworthy that fireballs with durations anything like comparable to that implied for Track C in BOI-485 (well over 1 minute) are very rare and spectacular events indeed. A reflection of such a spectacular fireball in surface water just might be plausible as an explanation of the light that streaked under the aircraft (even though the fireball itself still; ought to be more obvious than its reflection).

But as already mentioned, these events typically generate a great many reports. Like the St. Louis incident, such a spectacular fireball might be expected to be widely reported as a UFO in the clear skies of summer evening. But not one such report appears to have been generated elsewhere in the UK. Aside from the several local observations directly associated with this case, at Lakenheath and at nearby Ely, only one report has been discovered for the night of August 13/14 1956, which involved a totally unrelated sighting a few hundred miles away in Otterburn, Northumberland of what may have been the planet Venus. (There is a retrospective report of what sounds like a bright daytime meteor seen on a roughly south-north path over south London during one late morning around this date in 1956, appearing to go from the direction of Orpington, Kent, towards Greenwich. The witness believes it could have been the morning before the Lakenheath events. It is unclear whether the geometry could be consistent with the Perseid radiant, which would have been at moderately high elevation in the west at the time.)

If a local cause is more likely then we should consider an extremely local cause. Charles V. Metz, who at the time was a 1st Lt. with the 512th Fighter Interceptor Squadron at Bentwaters and one of the two airmen diverted to search for the slow cluster of targets NE of Bentwaters at about 2130 that night, recalled that over a period of several weeks in 1956 "balls of light" were seen on a number of occasions "floating slowly by the Tower" from the N end of the runway then climbing to about 500 feet and disappearing. The weather was cool, damp, slightly foggy under clear night skies. After much puzzlement it was eventually determined that the cause was car headlight beams from a slightly elevated road north of the base being scattered off a layer of low-lying mist. Metz was told that the lights were a well-known local phenomenon.

Could this or some similar effect - perhaps exaggerated in the retelling - have been responsible for the report that was passed to Lakenheath? It is possible; there is evidence in meteorological reports for the presence of coastal haze during the evening of the 13th, observed indeed by Metz and Rowe from the air, and appropriate conditions may well have existed at Bentwaters. The incident, it has to be said, rests on not much more than a hundred words of description in BOI-485, supported by a similar independent account by the Lakenheath RATCC Watch Supervisor. Both are quoting an unnamed military source or sources reporting by telephone. Written report IR-1-56 from Bentwaters, compiled much later, contains no comparable incident and no incident of any kind at the time originally reported, a fact which is highly interesting for various reasons but which is also unhelpful.

On the other hand, taking the contemporary official report of ground/air-visual sightings at face value and considering also the radar report, it remains true that the most natural and least contorted interpretation of the whole set of events would be in terms of a hypersonic luminous body overflying the field on a flat trajectory at an altitude of a few thousand feet. In a quantitative radar-visual model of Track C based on this hypothesis all the numbers dictated by various known factors are persuasively consistent. But this is only a circumstantial case. The source information is too scant to support a conclusion.

© Martin Shough 2003