Microbial Life and Astrobiology

• Goal 1: Understand the nature and distribution of habitable environments in the Universe
• Goal 2: Explore for past or present habitable environments, prebiotic chemistry and signs of life elsewhere in our Solar System
• Goal 3: Understand how life originates from cosmic and planetary precursors
• Goal 4: Understand how past life on Earth interacted with its changing planetary and Solar System environment
• Goal 5: Understand the evolutionary mechanisms and environmental limits of life
• Goal 6: Understand the principles that will shape the future of life, both on Earth and beyond
• Goal 7: Determine how to recognize signatures of life on other worlds and on early Earth

Source: http://astrobiology.nasa.gov/roadmap/

1. How Does Life Begin and Evolve?
   • Microbiology may be applied to the study of evolution at the molecular, organism, and ecosystem level.
   • Scientists at the Marine Biological Laboratory, for example, employ molecular techniques to explore how relatively simple organisms and their genomes (compared to those of metazoans) evolved into more complex forms. Their astrobiology program goal is to search for novel eukaryote diversity in rarely studied environments, some resembling conditions possibly existing millions/billions of years ago on other solar system bodies.
2. Does Life Exist Elsewhere in the Universe?
   • The discovery of microbes in extreme environments on Earth has changed our perspective regarding what makes a planet habitable. By looking at extreme microbes on Earth, we gain insight into the possible existence of extraterrestrial life.
   • The astrobiology consortium led by the Carnegie Institution of Washington primarily studies the physical, chemical, and biological evolution of hydrothermal systems. Looking at vent complexes associated with ocean ridges, deep aquifers, and other subsurface aqueous environments, they have successfully documented novel microbial metabolic strategies and unexpected high-pressure environments for life. This has led to the investigation of similar environments on other planets and bodies, as well as studies in planetary formation.
3. What is Future of Life on Earth and Beyond?
   • Microbes are essential players in the bioremediation of denuded areas on Earth (i.e., deforestation, mining). Knowledge of these processes can be applied in the terraforming of other planets.
   • Microorganisms have guided the way in developing our current atmospheric conditions. They carry out essential activities, such as the fixation of nutrients, and are necessary for the success of life as we know it.
   • Scientists at the SETI Institute are exploring the suitability of planets orbiting M stars for either single-celled or more complex life, as well as testing the survival of microorganisms in very high UV environments. Through the exploration of Earth's highest altitude lakes and ponds, in Bolivia and Chile, a series of investigations are examining the survival strategies employed by these microorganisms.