Open issues regarding the Turin Shroud

The Turin Shroud is a linen cloth which shows the front and back images of a man who had been scourged, crowned with thorns and crucified, who died on a cross and who was stabbed in the side with a lance after his death. The Catholic Christian tradition identifies him as Jesus Christ who was resurrected from the dead, but not all researchers are unanimous in believing this tradition, partly because science has not been able to give definitive answers to the questions of the identity of the Man and how the images were produced. There are many indications in favor of authenticity, but there are also still many open issues which do not allow us to reach a conclusion. This paper discusses these open issues, after presenting the very peculiar features of these \u201cimpossible\u201d images, in the hope that future scientific research in this direction will cast light on the most important Relic of Christianity. The bibliography relative to the Turin Shroud is copious, but it is not easy to find a summary of scientific issues still open regarding it. The present discussion frames the arguments debated in the papers of this Special Issue and will be also a useful tool to persuade more scientists to address research in these fields