Ringling Bros. and Barnum and Bailey Circus Train.

Ringling Bros. and Barnum and Bailey Circus Train. Image by Eli Christman / CC BY 2.0

Twenty-five-year-old Gemma Kirby marked a milestone in her daredevil career.

For the 500th time, she turned herself into a human cannonball to the delight of about 5000 spectators at a Circus XTREME, staged in Philadelphia by Ringling Bros and Barnum & Bailey.

A spokeswoman says the petite Minnesota woman, dressed in a sparkly silver outfit, shot out of the cannon, moved through the air at up to 66mph and landed safely in an air bag about 100ft away. The whole act takes about three seconds.

(Press Association)