Formation and evolution of the Solar System owe its substantially lower mass simply to having formed a few million years after Jupiter, when there was less gas available to consume. T Tauri stars like the young Sun have far stronger stellar winds than more stable, older stars. Uranus and Neptune are thought to have formed after Jupiter and Saturn did, when the strong solar wind had blown away much of the disc material. As a result, those planets accumulated little hydrogen and helium—not more than each. Uranus and Neptune are sometimes referred to as failed cores. The main problem with formation theories for these planets is the
Wheelers (novel) presence of gas giants may actually be a necessary factor in the formation of habitable terrestrial planets, as their mass deflects and breaks up potentially devastating threats. Earth-bound comets from outside the solar system tend to either slingshot past Jupiter and launch into hyperbolic orbits that take them far from the terrestrial planets, or may lose momentum and drift peaceably into the Sun. Without the incredible gravitational presence of Jupiter, it's possible that our planet would experience so many impacts and close calls as to prevent advanced evolution or even the formation of life. All the same, Jupiter also pulls