...so by the time the asteroid (or say the former Shoemaker-Levy 9) hits the planet, it gets disintigrated first in Jupiter's thick atmosphere and possibly little to no fragments of the asteroid got into the planet's real solid crust.

Now in Earth's case...I thought 2012 was an alien invasion. LOL

"Everything in this book may be wrong." Illusions: The Adventures of The Reluctant Messiah by Richard Bach