Reimar Johannes Baur

as Johannes Kepler

Trude Bechmann

as Keplers Mutter

Kurt Böwe

as Tycho Brahe

Karin Gregorek

as Margarete

Katharina Thalbach

as Ursula Haller

Rolf Hoppe

as Rudolf II

Eva-Maria Hagen

as Reinboldin

Barbara Dittus

as Stadtwächterfrau

Günter Schubert

as Stadtwächter

Fred Delmare

as Beutelsbacher

Carmen-Maja Antoni

as Gerichtsmagd

Friedrich Richter

as Michael Mästlin

Günter Junghans

as Longomontanus

Karla Runkehl

as Kristina Barbara Brahe

Arno Wyzniewski

Martin Trettau

Günter Grabbert

Dieter Franke

Manfred Zetzsche

Friedo Solter

Käthe Reichel

Gerd Ehlers

Erik S. Klein

Carl Heinz Choynski

Gert Gütschow

Hannjo Hasse

Jörg Panknin

Ernst Meincke

Thomas Langhoff

Jan Bereska

Jörg Knochée

Werner Dissel

as Richter