The earth was familiar to be a very violent planet, a planet that was once likely a lava world. Now after 4.5 billion years it has become a tempered planet. 75% of the surface is covered by water and hospitality of life. The earliest under-spirit evidence of life on earth was detected 3.5 billion years ago. About 1.5 million species have been identified but many more live on earth. In fact, many suggested that it might be 8. 7 million species living on earth. We, modern humans, are a part of this history only the last 200 thousand years. That is a very short time to compete with the first life form on the earth. If the Earth formed at midnight and the present moment is the next midnight 24 hours later, modern humans appear only at the last second. But what makes us so suitable for life, what are the key factors that made life possible on earth. Not every star makes a good candidate for making life possible on its planets. Our sun has just the right size. Stars are more massive than the sun, radiate more energy, and have assured the time spent, making life impossible to form their planets. Less massive younger stars are often unstable and prone to blasting a planet with vast amounts of radiation. The sun releases a tremendous amount of energy.