Anticipating the flight path of a bouncing object holds fascination for playing children and scientists alike. While the path of a ball can be judged easily, the erratic rebound behavior of complexly shaped forms are intriguing. Here, we focus on the timescales and rotation changes during real rock–ground impacts while traveling down a slope. Specialized sensors inside the rock track those changes and reveal contact times in the millisecond range defining the overall flight path behavior.