What evidence is there for large asteroids hitting earth like rock layers or fossil stuff or other stuff that the asteroid has left that is not usually found on earth but is abundant in space?
The so-called K-T boundary layer is the smoking gun that proved that large asteroids did strike the earth at intervals causing devastation beyond anything that man has seen in recorded history.
Go dig down to the geologic layer that separates the Cretaceous and Tertiary Periods (the K-T boundary) and you'll find the rare earth metal iridium, and in quantities far higher than in the rest of the rock around it. Do your digging anywhere on earth. The iridium is there. Whatever it was that crashed into earth some 65 million years ago had a lot of iridium in it.
The impact site was so large, and the event occurred so long ago that the earth "healed" the scar and it was difficult to detect. But now that we knew what we were looking for - a place where a big hole was punched in the lithosphere - we found it in Mexico and the gulf of the same name. Chicxulub. Yukatan, Mexico. How about a crater over a hundred miles across? Big enough?
Look at the moon. Why wouldn't the earth be subject to the same kind of pounding? Oh, we've got an atmosphere to help protect us, and we have both atmospheric and geologic phenomenon that will "erase" the damaged places in time. But the moon has taken some very large shots to the crust. So has earth. Why wouldn't it have had? And somewhere out there is a large rock with our name on it. We will get hit again. It's not a question of if so much as it's a question of when.
With the use of advanced space-based observation platforms, we've identified more locations where the cosmic hammer has struck. There is a lot of reading posted in various locations on the web for the curious investigator. A link is provided below, and it will take you to the Wikipedia post on the K-T boundry. Why not start there?