✔ 最佳答案
Scientists truly don't know. It's the current hypothesis being thrown around these days. The organic molecules had to come from somewhere, true enough. Whether they happen to form on the surface of the earth with or without celestial interference is anyone's guess. We weren't here billions of years ago to search for evidence in this matter.
One thing's for certain: We are all products of the universe. Our molecules were born from stellar material.