Rocketship X-M

Amid a race to establish a lunar military base, the first manned spaceship bound for the moon veers off course and lands on Mars. Col. Floyd Graham (Lloyd Bridges) and his crew explore the planet, discover that it has been ravaged by bombs and theorize that it was once inhabited by a once-thriving society that destroyed itself. Trying to piece together what happened, the five astronauts detect high radiation levels -- and then come face-to-face with strange cavemen-like creatures.