In 1619, after his involvement in the Ulm comet dispute, he published his work Fama Syderea Nova, containing prophecies in connection with the Great Comet of 1618 and the beginning of the Thirty Years' War. The Ulm comet dispute concerned whether the comets appearing during 1618 were signs sent by God, or just natural phenomena.
In 1619, after his participation in the Ulm comet dispute, he released Fama Syderea Nova, a document that contained prophecies about the Great Comet of 1618 and the beginning of the Thirty Years' War. The Ulm comet debate questioned whether these comets were signs from God or natural phenomena.