If we know what makes life on Earth habitable, we may be able to understand how to sustain life on other planets. Using our knowledge of life on Earth will allow us to learn more about other planets. It is important to compare life on Earth and life on another planet because they can be very contrasting. According to NASA, many missions have taken place and many more will continue in the future (Fletcher 2016). The large number of active missions shows the importance of a question like “Is there life?” maybe. This single question can turn into many other sub-questions, such as the questions described