Formation of the Earth and Moon: Influence of Small Bodies

The paper discusses a model of the bombardment Earth and Moon by small bodies when these planets were formed. It is shown that total ice mass delivered with to from feeding zone giant outer asteroid belt could have been comparable Earth’s oceans. Objects initially crossed Jupiter’s orbit become Earth-crossers mainly within first one million years. Most collisions originally located at distance 4 5 AU (astronomical units) Sun occurred during ten Some Uranus Neptune zones fall onto in more than 20 From their initial distances about 3 3.5 AU, some few billion years for takes into account only gravitational influence planets. ratio number collided varied 40 planetesimals terrestrial For Sun, this was range between 16.4 17.4. characteristic velocities 8 16 km/s, depending on values semi-major axes eccentricities orbits planetesimals. collision came Jupiter Saturn 23 km/s.