The Earth with all its unique features is truly a wonderful place to be. Our 4.6 billion years (age debated) old planet Earth that we live on has a surface area of 197 million square miles, of which about 70 percent of the Earth's surface is covered with water. The mass of the Earth is 5.97 x 10 24 kg and density is 5.5 g/cm3. This density makes the Earth the densest planet in the Solar System. The Earth we live on actually consists of 32% iron, 30% oxygen, 15% silicon, 14% magnesium and other elements like nickel, sulfur, calcium, aluminum, etc. To understand what is the Earth made of, we need to divide the earth up into convenient elements or piles. Let's have a detailed look. Read more on how was the earth created.