♃ What if Jupiter disappeared?
We lose a gravitational shield — and a shield-breaker. The truth is mixed.
The science
Jupiter's gravity deflects many comets away from the inner Solar System, but it also nudges some asteroids toward us. Modern simulations suggest its net effect is roughly neutral to mildly protective — the popular 'Jupiter as perfect shield' story is oversimplified.
Immediate consequences (modelled)
Almost nothing changes for Earth day-to-day; Jupiter's moons would scatter from their orbits.
Possible long-term consequences (hypotheses)
Comet and asteroid flux in the inner system would change over millions of years, in ways that need simulation, not slogans.
Assumptions: Jupiter vanishes without affecting the Sun or other orbits instantly.
Limitations: Does not model climate, geology, biology or engineering in full detail.
Reference: Horner & Jones, Jupiter shielding studies