Astronomers estimate that there may be a trill comet nuclei orbiting beyond Pluto. Why then do we not see more comets in our skies?
A) Most comets are so small that millions pass by the Earth completely undetected
B) Most comets have orbits that only bring them in toward the Sun as far as the orbit of Jupiter
C) Many comets collide with Jupiter each year and are thus not seen
D) Most comets remain in stable orbits beyond Pluto, only a few have their orbits disturbed and come into the inner solar system
E) All the missing comets are the reason so many people report seeing UFO's
Answer: A