Astounding She Monster, The (1957)

A trio of crooks kidnap an heiress, planning to hold her for ransom from her parents. As they flee Los Angeles into the San Gabriel Mountains, a probe sent by concerned inhabitants from a planet near the star Antares arrives with a meteor-like fiery tail. The driver of the getaway car sees its glowing female occupant and crashes while trying to avoid her. They spot the country house of Dick Cutler, a local geologist. They enter with guns pointing, hoping to impress his jeep into furthering their escape. But the alien woman appears at the window. One thug goes in search of her. He shoots at her. The bullets have no effect. She draws close, touches him and he dies quickly from radiation burns. The remaining two thugs force Cutler to drive them in his jeep, even though it is dark out and the headlights don't work. This leads to the remaining two thugs being touched by the she-monster. Back at the house, the geologist formulates a batch of aqua regia, a mixture of acids that he thinks will eat through her platinum skin and cause her to die.