Within most domains of discourse, there exists different terminology by distinct sub-groups. Often the terms used be, or have already been, organised into controlled vocabularies can be encoded into skos, a W3C standard representing vocabularies. This terminology can then used to help users to search for and discover resources. requires a search mechanism to go from a user-supplied to a vocabulary concept. this paper, we discuss the issues encountered in developing web service for searching and exploring the concepts skos encoded astronomical vocabularies. Our prototype takes in a query and responds with the concepts are the "best match". It then supports the user exploring the concepts' formal definition and alternative, as well as their relationship to other concepts. When add mappings between the concepts in different vocabularies (where available), these further enrich the explorations of vocabulary concepts. ESAIR 2009 Barcelona.