Science Opportunities - Basic Research Opportunities in Earth Science - page 49

and toxicity of these constituents. Such knowledge has important societal
and environmental implications in the Critical Zone, for example, in the
sustainability of agriculture and water resources.
Science Opportunities
The momentum associated with recent discoveries, improved facilities, and
new collaborations between disciplines offers a glimpse into future possibilities.
The coming decade will see the emergence of major opportunities for research on
Earth and planetary materials.
Development of Intense Neutron Beams and Other Powerful New Probes of
Material Properties
Neutrons are uniquely suited for documenting the molecular sites of
hydrogen (including water and hydroxide) in minerals and fluids; the textures of
rocks, soils, and other polycrystalline materials; the atomic configurations in
fluids; and the thermodynamic properties of crystals. Dedicated synchrotron X-
ray beamlines, fully instrumented for sophisticated in situ experiments, will lead
to an entirely new class of experiments with hundredfold or greater increases in
spatial, temporal, and spectral resolution. These technical developments will, with
little doubt, lead to breakthroughs in applied as well as basic research, from
monitoring fluid-mineral interactions to clarifying the evolution of planetary
interiors.
Retrieval of Samples From Other Planets, Interplanetary Space, and Comets
Future space missions, already initiated or planned, are expected to provide
samples of cometary, asteroidal, and solar materials that are representative of the
substances from which the planets formed. Specimens may also be returned from
Mars within 10-20 years. These samples will be small and are expected to contain a
significant fraction of dust-size particles, putting a premium on the use of modern
high-resolution analytical techniques. Mineral surfaces and interfaces will require
special study, especially to document potential precursors of biological molecules
and organic processes in extraterrestrial materials, which will be a high priority
for identifying any traces of life.