ntrated in Mercury's large core. The outer layer is made of sillicate rock similar to the Earth's mantle.VenusVenus is named after the Roman goddess of love. It is the second planet from the Sun and the brightest object in the sky other than the Sun and the Moon. It was once believed that life could exist in Venus but that has been proved wrong by various probes. In fact, Venus has the most hostile environment in the entire Solar System. The surface temperature is fiercely hot and the atmospheric pressure is crushing. One of the more apparent things that separate Venus from all the other planets in our solar system is that it rotates from east to west (all the other planets rotate from west to east). Because of this, Venus is said to be almost upside down. Conditions may have been better in the past. In the early stages of the Solar System, the Sun was not as bright as it is now and so Venus and the Earth would have formed similarly. When the Sun became brighter, the Earth was far enough away to escape serious damage but Venus was not. The surface temperature rose and the oceans dried up.EarthThe Earth, the third planet (rock) from the Sun, is the largest of the inner planets and also has the highest density. It is the only planet in the Solar System to be covered largely with water, the only planet with an atmosphere made up chiefly of nitrogen and oxygen and the only body that has a temperature suitable for life of the type that we know. It is also the only inner planet with a large moon - Mercury and Venus have none and the Martian moons are small. If the conditions on the Earth changed even slightly, the life as we know it could die out. The Earth's rotation period is not constant. It is slowly lengthening due to tidal friction between the oceans and the sea floor. This is caused by the influence of the Moon. Our MoonThe Moon has fascinated mankind throughout the ages. By simply viewing with the naked eye, one can discern two major ...
