Can a comet slow down?
This may be because sunlight caused ice on the comet’s surface to sublimate away into gas that then acted like a jet. If this jet fired in the opposite direction from the comet’s original rotational direction, it would slow down the comet’s rotational speed and eventually send it spinning in the opposite direction. The simplest explanation is that the comet’s spin slowed almost to a stop, and then powerful outgassing jets on its surface forced it to start rotating in nearly the opposite direction. When a comet gets close to the Sun, the heat makes its frozen ices turn directly into gas.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.