  The National Academy of Science Astronomy and Astrophysics Survey Committee,
in its new Decadal survey entitled Astronomy and Astrophysics in the New
Millennium, recommends, as a first priority, the establishment of a National
Virtual Observatory. The NVO would link the archival data sets of space- and
ground-based observatories, the catalogs of multi-wavelength surveys, and the
computational resources necessary to support comparison and cross-correlation
among these resources. This White Paper describes the scientific opportunities
and technical challenges of an NVO, and lays out an implementation strategy
aimed at realizing the goals of the NVO in cost-effective manner. The NVO will
depend on inter-agency cooperation, distributed development, and distributed
operations. It will challenge the astronomical community, yet provide new
opportunities for scientific discovery that were unimaginable just a few years
ago.
