In the proceedings of an international conference on extraterrestrial intelligence (Carl Sagan (ed.), Communication with Extraterrestrial Intelligence (CETI), Massachusetts Institute of Technology, 1973), one of the participants, G.M. Idlis, discussed the possibility of past visits to Earth by extraterrestrials. He dismissed most stories of such visits but said that "we have found a certain number of cases that do merit certain study . . . " He gave the following one as an example:

This is a case from a document published in 1842—that is 130 years ago when there was no discussion about CETI [communication with extraterrestrial intelligence]. That, of course, makes it all the more reliable. This is a report of a monastery clerk in Northern Russia addressed to a high dignitary of the Russian Church who reports that on August 15, 1663, there was a visitation of the earth between 10 and 12 hours from the clear skies. A sphere appeared, about 40 meters in diameter; from the lower part two rays extended earthward and smoke poured from the sides of the vehicle. The body disappeared and reappeared again, again disappeared and reappeared, changing in brightness in the course of these peregrinations. The phenomenon occurred over a lake and lasted for an hour and a half. At the place where the sphere touched the water, a brown film appeared, resembling rust. The phenomenon was observed by two groups of people. Some watched it from the church; others from a boat which happened to be in the middle of the lake.

There are of course problems when considering such old cases. For example, some of these stories were probably never meant to be interpreted literally and their real meanings can no longer be interpreted, as we do not know enough about the contexts in which they were written. This one, though, does give the impression of describing an actual event, although it is possible that the clerk who wrote the report was not a witness but was basing it on a distorted account of the incident.

Perhaps some readers might like to search for comparable reports in web sites listing UFOs interacting with water, such as UFO Casebook, and UFO Evidence, and Water UFO.