Much as in the US, with the recent congressional hearings on unidentified anomalous phenomena, the UK government is apparently less than transparent in its handling of UAP sightings (formerly called UFOs) – as your article about the Calvine photo shows (What really happened in Calvine? The mystery behind the best UFO picture ever seen, G2, 11 February). And, as in the US, any hope for imminent and trustworthy disclosure about what these objects may be is probably futile. Those who do not a priori consider this topic ludicrous, or exploit it in a sensationalist manner, are increasingly taking a more nuanced and independent approach. If there are such phenomena, it stands to reason that they can and should be studied with the necessary rigour. The unspoken implication is that at least a small proportion of these sightings may relate to what is called NHI – non-human intelligence. If that were to turn out to be true, the consequences for our worldview as the human species would make the Copernican revolution pale into insignificance. Serious research is more than warranted. I recommend Robert Powell’s new book, UFOs. It is a highly readable and scientifically solid introduction to the field of UAP studies. Your readers may also be interested in the interdisciplinary international symposium Grounding the SETI and UAP debate at Durham Law School on 24 April. It has taken astronomical research into SETI (Search for Extraterrestrial Intelligence) many decades to lose its stigma as pseudo-science and a reputation-wrecking endeavour. The same needs to happen for UAP research. Prof Michael Bohlander Chair in global law and SETI policy, Durham Law School As the person who first analysed the Calvine photograph for Dr David Clarke in June 2022, I am perhaps more familiar than most with the image. We should always remember there is no proof of where and when the Calvine photograph was taken, or who the photographer was. An Teampan mountain above Calvine is the most likely location, based on the original witness statement. However, we do not yet have an exact match. Dr Clarke’s team has traced someone with the same name as that on the back of the photograph, but they deny all knowledge of the incident. The available evidence suggests that the print and negatives were not “disappeared”, as some have suggested, but simply returned to the photographer or newspaper as the Ministry of Defence claims. What has disappeared is the original typewritten witness report faxed to the MoD by Craig Lindsay, along with the analysis produced by its image analysts, the Joint Air Reconnaissance Intelligence Centre. There is no credible evidence to support Sean Kirkpatrick’s suggestion that the photograph is the reflection of a rock in a lake, nor is it an image of a mountain top peeking through low-lying cloud as the MoD suggests. It should be noted that in 1992 British intelligence shared the photograph with the US Department of Defense, which undertook its own analysis. It would be interesting indeed if these missing documents were to be located and released. The Calvine story remains open for believers, sceptics and other interested parties to provide their own interpretations, and in this way a contemporary folklore of competing narratives has grown up around the image. Andrew Robinson Senior lecturer in photography, Sheffield Hallam University This is the level of reportage and analysis that the public is crying out for on “the phenomenon” (a catch-all phrase to cover the whole gamut of data, collected over eight decades, relating to something potentially non-human among us). More please. A series of articles would be very welcome: on Berwyn Mountain, Broad Haven School, Rendlesham Forest and more. Data is not evidence, and is certainly not “proof” of anything, but it must be gathered and interrogated properly. Aideen Carty Dublin, Ireland