What protective function is attributed to Jupiter's gravitational presence concerning long-period comets?

It sweeps the outer solar system clear by deflecting or capturing catastrophic objects.

In the later evolutionary history of the solar system, Jupiter functions primarily as a gravitational shield for the terrestrial planets. Its immense presence is likened to a bouncer or guard dog patrolling the periphery of the inner solar system. Specifically, Jupiter's gravity pulls potential collision threats, such as long-period comets and asteroids, away from Earth's orbital path. It either deflects them into the far reaches of the solar system or captures them into orbits that pose no immediate danger. This action is credited with reducing the long-term average rate of major impacts on Earth, providing the sustained periods of calm necessary for life to evolve past early sterilization events.