Teach Astronomy A Comprehensive Online Astronomy Education and Outreach Resource

A web site called Teach Astronomy (http://www.teachastronomy.com) has been created to serve astronomy instructors and their students, amateur astronomers, and members of the general public interested in astronomy. The content includes astronomy articles from an introductory level textbook and from the online resource Wikipedia, short video clips, astronomical images, podcasts, and recent news stories. This article describes the technology behind the delivery of those learning resources, which is relevant to the capabilities and limitations of the web site. One key innovation is the Wikimap, a Flash-based tool that presents the visual results of a real-time clustering analysis of hundreds or thousands of text items, displaying the item that best matches the search term and most closely related items. The clustering is carried out in a Lucene index, and it can operate on any database containing items of text. The astronomy content is routinely updated, in some cases daily. Due to the prevalence of smartphones, tablets, and other handheld devices, a simplified non-graphical version of the interface was developed using custom style sheets. Teach Astronomy has a large following of students taking introductory astronomy classes and members of the public with a recreational interest in astronomy. In the past year, there have been 250,000 unique visitors. Currently we are developing a new interface that uses HTML5 instead of Flash to display the Wikimap, an app version of the website for use on smartphones and tablets, and tool to support an instructor and learner community