A binary asteroid is a system consisting of two asteroids that are gravitationally bound to each other. These asteroids typically orbit a common center of mass, which is located outside of either body. Binary asteroids can vary in size and shape, and they provide valuable insights into the formation and evolution of celestial bodies in our solar system. Scientists study binary asteroids to understand their dynamics and the processes that lead to their formation. Some well-known examples include Didymos and its moonlet Dimorphos, which were observed during the DART mission. These studies help improve our knowledge of asteroid characteristics and potential threats to Earth.