Home > Report on Channel Islands UAPs > Conclusions | Traduction française

We have undeniably found some evidence suggestive of an atmospheric-optical explanation. In general "atmospheric-optical" means some effects on the propagation of light either by airborne particles (haze, mist or ice crystals) or by refractive index anomalies (unusual temperature gradients, causing mirage).

Unusual ice-halo effects are ruled out by the absence of ice in the line of sight. But there was a haze layer below the aircraft, probably associated with a weak temperature inversion in the CI area. That inversion would be the remnant of a much stronger advection inversion near the Breton coast, beyond the normal horizon, which was probably strong enough to form a localised optical duct.

Given the finding of a possible mirage-producing duct near the French coast one might feel that this cannot reasonably be a coincidence, and that mirage of sun-glitter on the sea near Brittany really ought to be a clear favourite. But we have placed this theory in Band 2 (barely plausible). Why?

In judging whether it is good method to scrap significant features of the observation other factors come into play, such as the internal consistency of the prima facie sighting geometry in Section 3, where by respecting the reported lateral motions we find

A mirage - even a scientifically unknown "lateral mirage in the free atmosphere" - doesn't explain these things in a natural way, whereas something like reflections on local haze, or lenticular clouds, or EQL in that area, could do so. And although Capt Patterson didn't see a high-definition object, he did see something of the right sort of shape and size and colour in the right place at the right time at the right apparent altitude (independently estimated), the like of which (he said) he had never seen before. It would certainly be preferable to take account of this sighting, too, if at all possible.

And preferring the haze-scattering theory does not mean that the potentially mirage-causing inversion on the Breton coast is a mere coincidence. The coastal advection duct is connected with the same warm NNE airflow producing the weak CI area inversion and the associated haze layer, so the coastal inversion is an indirect but necessary component of the haze-scattering theory, even if the light rays reaching the observers have not passed through that part of the atmosphere.

We think it would be exciting to be able to claim evidence of a completely new type of refractive index phenomenon, but we wish to emphasise that a mobile lateral mirage of the type implied would require horizontal temperature gradients of a severity and stability that seem inconceivable in the free atmosphere. Before adopting such a lateral mirage as a favourite one would wish to have ruled out the haze-scattering theory, the theory that observers were mistaken, and all other possible theories - including those that we have not yet thought of.

We are not convinced that the observations were mistaken, although we accept that this can never be ruled out by any objective test short of conclusively proving the presence of some phenomenon that explains them. During our investigation the overall cohesion and reliability of Capt Bowyer's account (in particular) has been tested in various small ways and it appears to us to have been careful and reliable. We think it possible that the UAPs did behave as described. This being so, we believe that the haze-scattering theory and the EQL theory are interesting alternative possibilities which could repay further study by experts

Home > Report on Channel Islands UAPs > Conclusions | Traduction française