The Yorp effect is a phenomenon in astrodynamics that refers to the torque experienced by a rotating celestial body due to the emission of thermal radiation. This effect can cause changes in the rotation rate and orientation of asteroids, comets, and other small bodies in space. The Yorp effect is particularly important in understanding the evolution of these objects and their potential for collision with Earth. Researchers study the Yorp effect to better predict the motion and behavior of these celestial bodies.