세상에서 가장 빠른 물체는 무엇인가?
In order to unambiguously express the speed of a spacecraft, a frame of reference must be specified. Typically, this frame is fixed to the body with the greatest gravitational influence on the spacecraft, as this is the most relevant frame for most purposes. Velocities in different frames of reference are not directly comparable; thus the matter of the "fastest spacecraft" depends on the reference frame used.
fastest spacecraft