The concept of remote access to large amounts of astronomical data from anywhere in the world, usually via a browser over the Internet. Standards for archiving data and the software to provide or display it are agreed by the International Virtual Observatory Alliance (IOVA). Virtual Observatory (VO) tools can be used for searching data archives, such as with the MAST (Mikulski Archive for Space Telescopes) facility located at the Space Telescope Science Institute (STScI) in Baltimore, Maryland, which provides data in the optical, ultraviolet, and near-infrared from space missions and observatories. Another use of the Virtual Observatory is to extract customized products to avoid downloading massive data sets. In this case, data analysis is performed at the location where the data are stored, with just the final results being transmitted to a user. At the Centre de Données astronomiques de Strasbourg (CDS) the Aladin interactive sky atlas is linked to other archives to give a view of the sky around a selected object. Software called VOEvent allows astronomers to find and activate robotic telescopes which can respond rapidly to transient events.

http://www.ivoa.net/ International Virtual Observatory Alliance website.

http://www.euro-vo.org/ European Virtual Observatory website.