Digitizing the skies

Charting the skies is the most ancient of astronomical pursuits. Now, in the spirit of the age, astronomers are busily paving their own information superhighways, and compiling digital road maps to guide them along. This happy activity was very apparent at a recent meeting, where we learned that numerous ambitious projects are being planned or are underway to map the sky at wavelengths ranging from the radio to the X-ray. Each digital survey will produce a census of all sources detected down to its appropriate flux limit, numbering thousands, millions or even billions.