Science Opportunities - Basic Research Opportunities in Earth Science - page 72

THE PLANETS
The Earth is only one member of a rapidly growing family of known
planets, both within and beyond the solar system. The extraordinary pace of
planetary exploration, driven by large national and foreign investments in
spacecraft and telescopes, is expected to continue for at least the next decade.
Current or planned space missions will provide unprecedented detail and
coverage of the geology, topography, structure, and composition of many solar
system bodies; in several cases this coverage will rival or exceed equivalent
terrestrial data. Similarly, it is anticipated that by 2010 the first samples collected
from Mars, a comet, an asteroid, and the Sun (via solar wind particles) will be
returned to Earth for direct investigation of their composition and structure.
Telescopic observations of primitive objects in the solar system (i.e., Kuiper belt
objects, located beyond the orbit of Neptune) and of the planets orbiting distant
stars promise to provide unique data regarding the origin and evolution of our
solar system.
Investigations of the solid Earth have usually been undertaken through
studies of the Earth itself. However, the study of extraterrestrial materials has
provided some of our most important insights regarding the Earth. For example,
the age of the Earth, 4.56 billion years, was derived not from dated Earth material
but by the study of meteorites (and subsequently confirmed by dating lunar
samples). The baseline for discussions of the bulk composition of the Earth is
likewise based on a meteorite (chondrite) reference. The richness of materials and
information on extraterrestrial bodies ensuing from the next decade of exploration
will provide important new opportunities for basic research into the origin,
evolution, and structure of planets, including Earth. Effective use of these new
data will require both a broad-based effort to promote interaction between the
Earth science and planetary science communities, and a substantial enhancement
of analytical capabilities.
Promise of Planetary Exploration
Robotic exploration of the solar system is increasing rapidly. The scientific
opportunities provided by these missions are detailed in a number of National
Research Council reports. 12 , 13 Here, the committee focuses on near-
12 An Integrated Strategy for the Planetary Sciences: 1995-2010. National Academy
Press, Washington, D.C., 199 pp., 1994.
13 The Exploration of Near-Earth Objects. National Academy Press, Washington, D.C.,
32pp., 1998.