THE VIRTUAL OBSERVATORY Astronomers have always been early adopters of technology, and information technology has been no exception. There is a vast amount of astronomical data available on the Internet, ranging from spectacular processed images of planets to huge amounts of raw, processed and private data. Much of the data is well documented with citations, instrumental settings, and the type of processing that has been applied. In general, astronomical data has few copyright, or privacy or other intellectual property restrictions in comparison with other fields of science, although fresh data is generally sequestered for a year or so while the observers. | 38 Grids and the virtual observatory Roy Williams California Institute of Technology California United States THE VIRTUAL OBSERVATORY Astronomers have always been early adopters of technology and information technology has been no exception. There is a vast amount of astronomical data available on the Internet ranging from spectacular processed images of planets to huge amounts of raw processed and private data. Much of the data is well documented with citations instrumental settings and the type of processing that has been applied. In general astronomical data has few copyright or privacy or other intellectual property restrictions in comparison with other fields of science although fresh data is generally sequestered for a year or so while the observers have a chance to reap knowledge from it. As anyone with a digital camera can attest there is a vast requirement for storage. Breakthroughs in telescope detector and computer technology allow astronomical surveys to produce terabytes of images and catalogs Figure . These datasets will cover the sky in different wavebands from y- and X rays optical infrared through to radio. With the advent of inexpensive storage technologies and the availability of high-speed networks the concept of multiterabyte on-line databases interoperating seamlessly is no longer outlandish 1 2 . More and more catalogs will be interlinked query engines will become more and more sophisticated and the research results from on-line data will be Grid Computing - Making the Global Infrastructure a Reality. Edited by F. Berman A. Hey and G. Fox 2003 John Wiley Sons Ltd ISBN 0-470-85319-0 838 ROY WILLIAMS Figure The total area of astronomical telescopes in m2 and CCDs measured in gigapixels over the last 25 years. The number of pixels and the data double every year. just as rich as that from real observatories. In addition to the quantity of data increasing exponentially its heterogeneity - the number of data publishers - is also .