We discuss in this section some highlights of the scientific returns we expect from a comparison of the results of the SDSS with those of various NASA missions. NASA has led the way in the provision to the astronomical community of large, well calibrated, easily used data bases and catalogues from NASA missions (e.g. the COBE, IRAS and HST archives) and from the literature (e.g. the NASA/IPAC Extragalactic Data Base). Some of the most fruitful areas of research in recent years have depended on the multiwavelength studies enabled by these data bases, such as the selection from the IRAS data bases of catalogues for optical redshift surveys, the analysis of the dynamics of rich clusters of galaxies from X-ray fluxes and optical redshifts, and countless other examples.
The data products which the Sloan Digital Sky Survey is expected to provide include:
The combination of the SDSS data with those from the NASA data bases will yield vast amounts of science; we discuss a small subset below. We emphasize that there are no formal agreements with any of these NASA projects with the exception of ROSAT, and that discussing them here in no sense amounts to an `endorsement' of the SDSS by these projects or an agreement by them to cooperate with us. Rather, informal conversations and exchange of information have been going on, with all parties fully recognizing the potential payoffs of this work.