Probably this was the case because of the natural=crater entry ? Because this could be any kind of hole. In this case it's just the "outer ring" of a meteor_crater. The question is IMHO whether it's "verifiable" (e.g. by a satellite picture, probably radar). Whether it's visible "on the ground" could be expressed using natural=*. Checked with my OsmAnd and couldn't see the ring. Possibly it depends on the map (layer) type ? There could also be some wiki examples how to map "exotic" meteor craters such as this one https://wiki.openstreetmap.org/wiki/File:Manicouagan-EO.JPG. This one will also not be noticed "on the ground" https://www.openstreetmap.org/way/1063229590/history