Ever since early humans first looked skyward and imagined the stars as distant campfires, humanity has wondered if we are alone in the Universe. The ancient Greeks argued against our home planet being the only cradle for life, but lacked the technology to prove their beliefs. In the late 20th century, the near-simultaneous discoveries of the possible remains of bacterial life in a Martian meteorite, and the first planets orbiting other stars, brought the question of the existence of life beyond the Earth to the forefront of scientific endeavor. In the 21st century, the new field of Astrobiology harnesses the required technological and scientific capability to seriously address this ancient and fundamental question.
Astrobiology is the study of life in the universe. The search for life beyond the Earth requires an understanding of life, and the nature of the environments that support it, as well as planetary, planetary system and stellar processes. To provide this understanding, astrobiology combines the knowledge and techniques from many fields, including astronomy, biology, chemistry, geology, atmospheric science, oceanography and aeronautical engineering. How to become an astrobiologist can work alone on particular scientific questions, but often astrobiologists from different scientific disciplines work together to examine complex questions that no one field can answer alone. These questions cover topics such as:
- How does life originate?
- How does life evolve?
- What kind of environment is necessary for life to survive?
- What are the environmental limits or “extremes” under which life can survive?
- What might life look like on another world?
- Is there or has there been life elsewhere in our solar system?
- How can we observe and identify a habitable – or even inhabited – world?
- What is humanity’s future on Earth and beyond?