At www.irishcentral.com/roots/history/Ancient-Irish-recorded-worlds-first-e… … enigmatic images on a slab of stone at the back end of a cairn on
Loughcrew are said to illustrate a solar eclipse. Brennan and Roberts discovered the Sun illuminated the chamber at Samhain and again, at Imbolc, the Celtic cross quarter days. It is admitted this may not have been the original alignment – but this is not elaborated on at the link above. The theory is that these ancient cairns were constructed, in part, to record solar eclipses – which seems a lot of work for a fairly regular occurrence that was quite harmless to humans living on the surface of the Earth. By the same reasoning, or way of thinking, the claim is that the Festival of Light was celebrated in order to welcome eclipses. This sounds more hippy than science – and perhaps it is. As we are talking about a stone with symbols of concentric rings and cup marks we may take this with a pinch of salt. Even if the astronomer-priests were able to predict eclipses – one would hardly go to so much trouble. Cup marks are also engraved on the slab of stone (which may have existed as rock art prior to being adopted as the back wall of a cairn) and the authors fail to mention a tentative connection with comets and meteors.
Brennan and Roberts observed the full moon illuminating the end recess of the cairn but nobody has researched the movements of the moon in relation to the age of the monuments at Loughcrew.