Being eventually protected from traceable asteroids is great. These, however, are in some type of repeating orbit. They are calculable.

Current theory has it that the Earth is made up of two distinct planets. Billions of years ago, Earth, at the time bit smaller than Mars, was struck by a rogue planet, also a bit smaller than Mars. Earth was liquefied in the impact, but had also suddenly become a lot bigger and the two cores joined. The splash from this event congealed into the Moon.

Rogue planet.

At the moment, the solar system is passing through a very thin vacuum, a sphere of clean space blown empty by a super nova from a few million years ago. It is believed this reprieve from rogue events may continue for the remainder of this century. What makes the rogue so dangerous is that it travels from outside the solar system on a direct trajectory. A sniper shot. There is no parabolic to it.

It's huge. We see it, then we're hit.