What would be a good thesis question about meteors, comets, and asteroids?
How about “Compare and contrast the composition, orbit and origins of meteors, comets and asteroids.” You could look at each of these distinct groups. Meteors (or meteroids) are rocks of various sizes which are wandering through space, and have periodically been caught in the earth’s gravitational field and hit the planet. A meteor impact is thought by many to have wiped out the dinosaurs. Comets are lumps of ice and other material, originating the Oort cloud beyond Pluto, and occasionally being knocked out of their orbit into large elliptical orbits in which they approach the sun and start melting, the flourescent gases they produce glowing and also producing the tail. Asteroids are essentially planetoids (larger than rocks but smaller than planets) mainly in a stable orbit around the sun between Mars and Jupiter. They are thought to be remnants of the initial debris of which the solar system was made, which did not coalesce into a planet because of tidal forces exerted by Jupiter.
