In the universe compounds such as water and elements such as carbon are both unlimited in space. Even a Michael Lemonick, a science writer, claims that “life on other worlds, like life on Earth, will be built from complex molecules that incorporate carbon as an essential part of their structures -- and use water as a solvent. One reason is that carbon and water are abundant throughout the Milky Way”(2014, par. 37). The universe is about 13.8 billion years old and earth is 4.5 billion years old, which means that it takes time for life to take form. Scientists have even calculated that there are “100 BILLION PLANETS TOTAL[.] 50 BILLION SMALL PLANETS*[.] 17 BILLION EARTH-SIZE PLANETS[.] 11 BILLION EARTH-SIZE PLANETS IN STARS' HABITABLE ZONES**[.] …show more content…
What is necessary for life to exist is that carbon and water must be present to form complex forms of extraterrestrial life. This actually makes sense that those two elements are needed since first of all like for example most living things on earth are made of carbon. Living things need carbon in order to grow, reproduce, and most importantly to live. Carbon is a finite source which means that there is only so much of it and it cycles through earth in many forms. This makes carbon available to living organisms and it balances with other chemical reactions in the atmosphere and in bodies of water like lakes, ponds, rivers, and oceans. Equally important water is important due to the fact that it is essential for life to survive. Any type of organism from micro to macro, all contain water. If no water existed on planet earth than life would not exist since plants and animals, including humans, make up life on earth. And “[p]lanets similar to Earth in size and distance from their sun — ones likely to have oceans of water — represent the most plausible homes for carbon-based life in other solar