While sorting through old slides of the total lunar eclipse of September 16, 1997, to digitally duplicate them, I noticed a light blue dot in the Mare Tranquillitatis in the frame at the end of totality (19:18 UT).At first, I thought of a hot pixel produced by the DSLR, but the blurry appearance of the same order as the lunar details led me to exclude this possibility. Indeed, the intriguing detail was present in the slide and does not even appear to be a flaw.The most obvious hypothesis is a transient, such as a meteorite impact exactly during totality. It is not a crazy hypothesis since, during the eclipse of January 21, 2019, thousands of observers were able to observe and photograph this type of event.Being a film shot, the exposures were also longer than digital ones, increasing the likelihood of the occasional shot.I invite anyone who took shots during that eclipse, around the indicated time with a difference of a few minutes, to check their images because it would be a very interesting observation and historically among the first recorded. If so, contact me and I encourage sharing. (Image correctly oriented north at the top and east on the left, 10 second shot with 114/900 with 400 ASA slide)