In this chapter we present an overview of NASA's Planetary Data System project with emphasis on the Small Bodies Node (SBN) and describe a separate relational database project, the Steward Observatory Asteroid Relational Database (SOARD). We summarize the datasets that are currently available through SBN and SOARD as well as those planned to be ingested in the future. Procedures for accessing data from the SBN and SOARD via Internet are included.

Databases of astrometric and orbital data for minor planets and comets and of photometric data for comets are maintained in connection with the publication of the Minor Planet Circulars and the International Comet Quarterly. Aspects of these publications and the content and availability of these databases are discussed.

The second part of the Comet Light Curve Catalogue/Atlas (CLICC/A) has been made available by anonymous ftp. This database contains magnitude estimates of periodic comets, reduced to a geocentric distance of 1 AU and corrected for observational effects. The database is described in some detail.

Since it was founded early in the 1980′s, the IAU Meteor Data Center (IAU MDC) has accumulated a large number of the meteoroid orbits measured worldwide so as to make these freely available to all interested researchers. The total number of orbits available is about 68,000, of which about 6,000 were determined using optical techniques (photographic or TV), the bulk having been detected using decameter radars. The observation sites range from various locations in the U.S.A., Canada, Australia, and in the former Soviet Union and Czechoslovakia; radar orbits from the Soviet Equatorial Expedition to Somalia are also archived. About 39,000 of the 62,000 radar orbits are derived from the Harvard Radar Meteor Project. Most of these programs were carried out during the 1960's and 1970′s, but still represent our best knowledge of the orbital distribution of interplanetary particles in the size range from 100 μm to 1 meter. A new survey currently in progress in New Zealand has so far rendered over 350,000 orbits, and it is anticipated that these will soon become available through the IAU MDC. Presently the 68,000 orbits archived in the IAU MDC are only available on magnetic recording media, but it is planned that they will shortly be made accessible via anonymous ftp.