"In the basement of a quaintly cramped building on the Harvard University campus, down a set of corkscrew stairs that would make a rollercoaster designer dizzy, the shelves and filing cabinets are spilling over with 100 years of stars. Glass photographic plates shipped from telescopes around the world [including Arequipa] document the Beehive Cluster as it appeared in 1890, or Cepheid variable stars as they looked in 1908.
The glass plates - some 525,000 of them - serve as the only permanent record of the skies as seen by our forebears. But the 150 tonne database represents much more than an archive of astronomical history - it's a potential gold mine for new discoveries, if only scientists could dig through it. With that goal in mind, a small collection of astronomers and archivists is using custom-built technology to bring this enormous data set into the digital age.
When they're finished in three or four years, the archive will consume 1.5 petabytes of storage. Any astronomer with web access can click on a star catalogue and pull up an individual star's light curve, showing how it has brightened or dimmed over time. ...
An LED light source illuminates the plate emulsion in 8-microsecond bursts, and a CCD camera captures 60 overlapping images for each 20 x 25 plate. The final resolution is 11 microns per pixel, or 2,309 dpi - captured in 92 seconds. Put another way, in a minute and a half, the machine generates about the same amount of data as contained on a DVD for a typical hour-and-a-half movie."
http://www.popsci.com.au/science/ast...scanner-darkly
http://tdc-www.harvard.edu/plates/
http://hea-www.harvard.edu/DASCH/
