How Does Life Begin and Develop?
Objective
1
Sources of 0rganics on Earth
Objective
2
Origin of Life's Cellular Components
Objective
4
Genomic Clues to Evolution
Objective
5
Linking Planetary and Biological Evolution
Does Life Exist Elsewhere in the Universe?
Objective
7
The Extremes of Life
Objective
8
Past and Present Life on Mars
Objective
9
Life's Precursors and Habitats in the Outer Solar System
Objective
10
Natural Migration of Life
Objective
11
Origin of Habitable Planets
Objective
12
Effects of Climate and Geology on Habitability
Objective
13
Extrasolar Biomarkers
What is Life's Future on Earth
and Beyond?
Objective
14
Ecosystem Response to Rapid Environmental Change
Objective
15
Earth's Future Habitability
Objective
16
Bringing Life with Us beyond Earth
Objective
17
Planetary Protection
Question: Does Life Exist Elsewhere in the Universe?
The Extremes of Life
Objective 7: Identify the environmental limits for life by examining biological adaptations to extremes in environmental conditions.
The habitable zone is defined ultimately by life's capacity to adapt to extremes in key environmental parameters. For example, Mars' habitability is severely constrained by low temperatures, low water potential, and damaging photochemical reactions. The hazards of extreme conditions can be mitigated by biochemical and structural countermeasures within cells, and by processes at the ecosystem level. An effective research program will combine studies of natural ecosystems, physiology, and genetics with the development of new research technologies and missions for the exploration of extreme environments--first in our own Solar System and later, beyond.
Implementation
Near- to Mid-Term:
- Identify and characterize the
biota in those extreme environments on Earth that are most relevant
for a search for life on Mars and Europa.
- Define more completely the
range of strategies for obtaining biochemically-useful energy.
- Define the mechanisms that
cells and ecosystems have evolved to survive the extremes in environmental
conditions.
- Define the potential for fossilization
and preservation of biota in extreme environments.
- Determine whether the life forms from extreme environments on Earth could exist in other planetary environments.
Future extensions:
- This research will will help to define more completely the full range of life's capacities for survival. It will lead to more effective strategies to search for life beyond Earth, because it will aid in the selection of sites for exploration, and it will optimize our ability to recognize evidence of life and its fossils.