The visual manifestation of the recent Hale-Bopp comet reminds us how telling those rare objects which suddenly flare in the sky. One can suppose ancient people living by natural light were more compellingly struck by the sight of comets and supernovae, and understandably researchers seek images of them in the shapes of rock-art motifs. An absolute dating contradicts that supposition in respect of a presumed image of the visible supernova of AD 1054.
However, radiocarbon dates on three of the figures, 230 ± 70, 330 ± 50, and 840 ± 70 years BP, were much too young for the images to have represented that event. 41 Similarly, there were two other instances in which the plasma chemical dates differed significantly from those based on archaeological inference. However, these dates were obtained on charcoal-pigmented drawings, and we have no reason to suspect the radiocarbon dates.