Quick Answer
Removing Jupiter would change the gravitational architecture of the Solar System. The orbits of asteroids, comets and the other planets would slowly evolve differently. It would not automatically cause Earth to be bombarded or become safer; Jupiter both redirects some objects away from the inner Solar System and can also perturb objects onto Earth-crossing trajectories.
The Solar System loses a major gravitational mass
Jupiter contains more than twice the mass of all the other planets combined. Removing it would therefore change the gravitational field of the Solar System, although the effect on Earth would be indirect because the Sun remains overwhelmingly more massive.
Earth's orbit would change only slightly at first
Earth's main orbit is controlled by the Sun. Jupiter does contribute small perturbations, so removing it would gradually alter the detailed trajectory of Earth and the other planets rather than sending Earth flying away immediately.
Asteroids would be reshuffled
Jupiter's gravity strongly shapes populations such as the main asteroid belt and influences resonances. Without it, those populations would evolve along different paths, with major consequences for the long-term delivery of small bodies into the inner Solar System.
Is Jupiter Earth's shield?
The popular idea that Jupiter simply protects Earth is incomplete. Jupiter can eject or capture some comets, but its gravitational perturbations can also redirect objects toward the inner Solar System. Simulations show that its net effect depends on the population of objects being studied.
SpeculativeThe exact long-term impact on Earth's impact rate is model-dependent. There is no simple rule that removing Jupiter would either dramatically increase or dramatically decrease impacts.
The Solar System over millions of years
Planetary systems are chaotic over long intervals. Without Jupiter, resonances and orbital interactions would be reorganized, changing the architecture of small-body populations and the detailed evolution of the planets.
The bottom line
Jupiter's disappearance would not cause an instant catastrophe on Earth. Its biggest effect would be a slow restructuring of Solar System dynamics, especially the orbits of asteroids and comets.
Jupiter is the most massive planet in the Solar System, so removing it would change the gravitational environment of many smaller bodies. Asteroids, comets and some planetary orbits would gradually respond to the missing gravitational influence. Earth would not suddenly fly out of the Solar System: the Sun remains overwhelmingly more massive and continues to dominate Earth’s orbit.
What would actually change?
A note on our approach: Every article on WhatIfLab separates what current science establishes from what remains genuinely speculative. Where we cite a figure or finding, it reflects published, mainstream research at the time of writing — not a prediction dressed up as fact.