All of the above are part of the nebular theory. The largest asteroid is Ceres, which is about 1000km in diameter. Asteroids are thought to be the leftover planetesimals of the inner solar system that never formed a planet. There is no evidence that large meteorites have ever hit the earth. Most meteor showers occur when the earth passes through the debris tail left behind by a comet.
Comets originate from sources outside the solar system.
The nucleus of a comet is best described as a dirty iceball. The coma is a cloud of gas and dust surrounding the nucleus and appears only when the comet approaches the inner solar system. Short Answer Questions Briefly describe the nebular model for the formation of the solar system. Describe the Asteroid Belt, where is it, what are the types of objects are in it, what is the range of sizes of the objects and any gaps in it. List the planets in the solar system in order from closest to the sun to farthest.