Goal 3
Understand how life originates from cosmic
and planetary precursors.
Perform observational, experimental and theoretical investigations to understand the physical and chemical principles underlying the origin of life, both on the Early Earth and on other planetary bodies.
How life began on the Earth remains a fundamental unsolved question. The NASA charter identifies understanding the origin and distribution of life in the universe as a primary research goal, and we can now perform a variety of integrated research activities that will lead toward achieving that goal. We must also be aware that the origin of life on Earth is likely to represent only one way among many in which life can begin. Thus we must attempt to understand the universal principles that underlie not only the origins of terrestrial life, but also the possible origins of life elsewhere. We seek to understand these principles by determining what raw materials of life can be produced by chemical evolution on planetary surfaces and atmospheres, and what extraterrestrial materials can be delivered during late accretion. We should attempt to understand how organic compounds can assemble into more complex molecular systems and the processes by which complex systems evolve those basic properties that are critical to life's origin: capturing energy and nutrients from their environment, and manufacturing copies of themselves. We must also incorporate clues from the evolutionary tree and fossil record, and the full range of microbial life in diverse environments to understand better the physical limits of the living state.
- Objective 3.1—Sources
of prebiotic materials and catalysts. Characterize
the cosmic and planetary sources of matter (organic and inorganic) for
potentially habitable environments in the Solar System and in other
planetary and protoplanetary systems.
- Objective 3.2—Origins
of functional biopolymers. Identify
multiple plausible pathways for the condensation of prebiotic monomers
into polymers with the potential for catalytic and genetic functions,
and mechanisms for their assembly into more complex molecular systems
having specific properties of the living state.
- Objective 3.3—Origins
of energy transduction. Identify
prebiotic mechanisms by which available energy can be captured by molecular
systems and used to drive primitive metabolism and polymerization reactions.
- Objective 3.4—Origins
and early consequences of cellularity. Investigate
both the origin of membranous boundaries on the early Earth and the
associated properties of energy transduction, transport of nutrients,
growth, and division. Investigate the origins and early development
of mechanisms of translation and transcription. Investigate primitive
processes leading to heterogeneous populations of cells.