Science Goals Answer 3 Major Questions
The Astrobiology Program at NASA defines Astrobiology as "the study of life in the universe." To pursue this study, researchers attempt to answer 3 major questions surrounding 10 science goals:
How did life begin and develop?Scientists answering this question attempt to (a) determine how life arose on the Earth. Were the chemicals necessary for life brought to Earth by comets? Did life start at the hydrothermal sea vents, in a dilute chemical-soup ocean, or around dry beaches/lagoons? (b) Understand the principles governing the organization of life into living systems. Where is the line drawn between prebiotic and biotic? How was that line crossed to form life? (c) Understand how life evolves on the molecular, organismal, and ecosystem scales, especially in response to changes in the Earth's environment and gravity. (d) Determine how the Earth's biosphere co-evolved with the Earth. How did the coming of life change the early Earth's atmosphere and water chemistry, etc?
Does life exist elsewhere?
To answer this question, researchers need to (a) determine the limits for life in Earth environments to better define where we should look for life elsewhere. Under what conditions can life survive? For how long? Do we see those conditions on any other planetary body? (b) Understand what makes a planet habitable and determine how common habitable planets are in the universe. Is liquid water really necessary? What other things does life need to survive? (c) Determine how to recognize life on other worlds. Is just finding water a indication of life? What other chemicals might suggest life is present? (d) Determine is life was or is present on other worlds, especially in the solar system. Is there life on Europa? Was there life of Mars, and is there today?
What is the future of life on Earth and beyond?Scientists interested in this question must (a) learn how ecosystems respond to environmental changes on human timescales. Do the things we do - using cars, building factories, burning fossil fuels - create rapid changes in ecosystems? (b) Understand how Earth life lives in space and on other worlds. How does the human body respond to zero gravity? Can plants grow with no gravity? Will humans be able to life on Mars?