From Ian Ridpath to Dave Clarke, 15 January 2001

A few comments about Perseid meteors and other astronomical aspects of the Lakenheath case.

Yes, it is possible that bright Perseid meteors were seen on the night in question, which was only a day past the traditional Perseid maximum. The numbers would be likely to increase as the night wore on and the radiant point got higher in the sky.

Meteors would have appeared to emanate from the Perseid radiant in the northeast and could have headed off from there in any direction.

I don't know whether 1956 was a particularly good year for Perseids -- I will try to find out for you -- but the Perseids always put on a good show with a high proportion of bright events.

The Moon would have set that night at 11.12 pm BST as seen from that location (are the times in the files GMT or BST?). I note that a bright object was seen hovering in the SSE, which Klass identifies as Mars.  This is indeed the most likely identification. Mars was at that time the brightest object in the sky, and rose at 9.50 pm BST.

Meteors do leave ion trails which reflect radio waves, but at altitudes of around 100 km, so I would doubt that conventional radar would pick them up. If it did, why don't we get such reports all the time?

You may not have a copy of Menzel's 1977 book The UFO Enigma. He mostly summarizes Klass's discussion of the case, but adds his own explanation as follows:

"Our solution to this sighting is based upon what is called "anomalous propagation" (AP). The ground radar signal bounced from the plane to some unidentified ground target, thence back to the plane. Ground radar thus registered two blips: one was directly from the plane and the other a delayed echo from the plane via the ground. However, the long-delayed *second* echo was from an earlier pulse sent out by the same transmitter on the ground. The two blips kept pace with each other because the plane (the moving target) was implicated in both signals."

From Ian Ridpath to Dave Clarke, 19 January 2001

I have asked Neil Bone, director of the British Astronomical Association's meteor section, if there is anything in their records concerning levels of Perseids in 1956. As you'll see from his reply below, there's no indication of exceptional activity in 1956. In any case, the night of August 13/14 was two days after the peak in those days.

He does, though, make the interesting point that solar activity was high around that time. I don't know whether this would have had any effect on radar propagation, but it might just be relevant.

ATB,
Ian

* * *

Neil Bone's reply:

"At that time, Aug 13-14 would, if anything, have been less active than at the current epoch - the maximum gets slightly later with each passing year, and if you look at the literature of the time, Aug 11-12 was generally regarded as the peak night in them days! So, we're some way off the best activity, and the probability is that it'd have been fairly 'normal' anyway - perhaps of the order of 20 per hour at best at that stage.

"I've run an almanac program against the date, and find that the Moon would have been at First Quarter on 1956 Aug 13 (I don't recall - I was minus three at the time), so skies would have been dark if nothing else.

"A likelier explanation than the Perseids for unusual sightings may, of course, lie with the aurora. In particular, 1957 - a year later, and the start of the IGY period - produced some staggering displays, the like of which only occur once in a while (1989 March and last April perhaps being the only comparably widely-visible events in recent time). It's not implausible that there was good auroral activity penetrating to lower latitudes by the autumn of 1956, though I don't have anything specific in my records to indicate it."