The Spanish Air Force has declassified 55 UFO cases — of those, just four have an “A” designation, meaning they were subject to lengthy investigation. The first involved a transparent sphere with “Swedish-looking” occupants wearing divers’ suits above the Canary Islands in 1976, we covered that here.
The second of these “A cases” is even more unbelievable.
In 1977, a carpenter, Juan Sillero, says a 20-meter wide saucer landed near his home outside Gallarta, Spain. He told investigators a craft came four other times, one of which he went onboard and interacted with beings that looked human. They told him they were there “to help Earth” because it was “going out of its orbit and tilting too much.”
Sources in order of mention
Avistamiento de fenómenos extraños en Gallarta (Vizcaya), 02.13.1977, Spanish Air Force: http://bibliotecavirtualdefensa.es/BVMDefensa/exp_ovni/i18n/consulta/busqueda_referencia.cmd?campo=idtitulo&idValor=395886
List of 55 anomalous phenomena: http://bibliotecavirtualdefensa.es/BVMDefensa/exp_ovni/i18n/catalogo_imagenes/grupo.cmd?path=137829
Avistamiento de fenómenos extraños en Talavera la Real, 01.14.1975, Spanish Air Force: http://bibliotecavirtualdefensa.es/BVMDefensa/exp_ovni/i18n/consulta/resultados_ocr.cmd?buscar_cabecera=Buscar&id=5412&tipoResultados=BIB&posicion=2&forma=ficha
Avistamiento de fenómenos extraños en la base aérea de Talavera (Badajoz), 11.12.1976, Spanish Air Force: http://bibliotecavirtualdefensa.es/BVMDefensa/exp_ovni/i18n/consulta/resultados_ocr.cmd?buscar_cabecera=Buscar&id=5412&tipoResultados=BIB&posicion=1&forma=ficha
Stabilization of the Earth’s obliquity by the Moon, Laskar et al (1993), Nature: https://www.nature.com/articles/361615a0