Comets go around the Sun in a highly elliptical orbit. They can spend hundreds and thousands of years out in the depths of the solar system before they return to Sun at their perihelion. Like all orbiting bodies, comets follow Kepler's Laws - the closer they are to the Sun, the faster they move.
Justified means if something is right or that it's good or the right thing to do. The quote sounds like it's too much. So I would say no, it's not justified.
