- Gunnar Tolnæs
- Avanti Planetaros - Captain of the Space Ship
- Zanny Petersen
- Corona - Avanti's Sister
- Nicolai Neiiendam
- Prof. Planetaros - Astronomer
- Alf Blütecher
- Dr. Krafft - Avanti's Friend
- Svend Kornbeck
- David Dane - American
- Philip Bech
- Martian Leader - Wise Man
- Lilly Jacobson
- Marya - Martian Leader's Daughter
- Frederik Jacobsen
- Prof. Dubius
- Albert Paul
- (voice)
- Nils Asther
- Wounded Martian Citizen
- Alfred Osmund
- Martian Priest
