Jupiter removes about a million asteroids from Earth's path

Jupiter being Earth’s “guardian” is only half the story — the same gravity that carved the Kirkwood gaps can also shove asteroids into Earth-crossing orbits. Yes, it literally shredded Comet Shoemaker‑Levy 9 on camera in 1994 and likely helped drain the asteroid belt (Dawn data backs the long-term sculpting), but Jonathan Horner’s peer‑reviewed models say a smaller or differently placed Jupiter could mean fewer impacts on Earth. Between Grand Tack vs Nice model chaos and the messy Late Heavy Bombardment debate, Jupiter might be shield, threat, or both — and scientists still don’t agree which.