Geology of solar terrestrial planets of heavier elements contained in the solar nebula. The four inner or terrestrial planets have dense, rocky compositions, few or no moons, and no ring systems. They are composed largely of minerals with high melting points, such as the silicates which form their solid crusts and semi-liquid mantles, and metals such as iron and nickel, which form their cores. The Mariner 10 mission (1974) mapped about half the surface of Mercury. On the basis of that data, scientists have a first-order understanding of the geology and history of the planet. Mercury's surface shows intercrater plains, basins, smooth plains, craters, and
Stranger from Venus field. This disruption would then affect the orbits and gravitational fields of all the other planets in the solar system. The stranger makes a promise that if Earth eliminates these dangers, Venus will share some of its higher scientific knowledge with our scientists. During the meeting, however, the man from Venus concludes that humanity is not yet ready to receive such advanced knowledge. After his communication disc is stolen, which allows him to contact the approaching Venusian ship, the stranger quickly realizes that an interplanetary meeting of minds can never take place. He also learns that such a meeting will