In the coming era of data-intensive science, it will be increasingly important to be able to seamlessly move between scientific results, the data analyzed in them, and the processes used to produce them. As observations, derived data products, publications, and object metadata are curated by different projects and archived in different locations, establishing the proper linkages between these resources and describing their relationships becomes an essential activity in their curation and preservation. In this paper we describe initial efforts to create a semantic knowledge base allowing easier integration and linking of the body of heterogeneous astronomical resources which we call the Virtual Observatory (VO). The ultimate goal of this effort is the creation of a semantic layer over existing resources, allowing applications to cross boundaries between archives. The proposed approach follows the current best practices in Semantic Computing and the architecture of the web, allowing the use of off-the-shelf technologies and providing a path for VO resources to become part of the global web of linked data.