Travelers In The Night

From our vantage point on planet Earth asteroids appear as moving points of light which strictly follow the law of gravity as they orbit the Sun. On the other hand comets appear as gas clouds which sometimes deviate from their gravitational orbits when they burp bursts of gases as they are warmed by the Sun. Dark comets appear as points of light like asteroids but move through space as though they are influenced by small rocket like bursts of volatile materials in cometary fashion.