'Convent'ional Sighting? (April 1)

The police answered a call from the local convent about a strange object circling overhead. When the officer arrived, he asked the Mother Superior what kind of object it was. "I can't say", she replied, "but sister Elizabeth says she knows exactly what it was, do you want to speak with her?" 


"That's ok", said the policeman, "I'll just put it down as a nun-identified flying object."