Solar System the early Solar System, but they either merged or were destroyed, leaving the planets, dwarf planets, and leftover minor bodies. Due to their higher boiling points, only metals and silicates could exist in solid form in the warm inner Solar System close to the Sun, and these would eventually form the rocky planets of Mercury, Venus, Earth, and Mars. Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large. The giant planets (Jupiter, Saturn, Uranus, and Neptune) formed further out, beyond the frost line, the point between the orbits
Terraforming of Venus intervention for the purpose of building colossal mountains on Venus to serve as islands of colonization in the skies of Venus. Since Venus only has a fraction of the water on earth (less than half the earth's water content in the atmosphere, and none on the surface), water would have to be introduced either by the aforementioned method of introduction of hydrogen, or from some other extraplanetary source. Paul Birch suggests the possibility of colliding Venus with one of the ice moons from the outer solar systems, thereby bringing in all the water needed for terraformation in one go. This