What alien planet is represented by this picture? Would it surprise you to learn that the picture represents Earth? After Earth first formed about 4.6 billion years ago, it may well have looked like this. Instead of rivers of water, rivers of molten rock flowed over its surface. Life as we know it could not have survived in such a place. How did this fiery hot planet become today’s Earth, covered with water and teeming with life? The long and incredible story of Earth’s history is told in this chapter.