If, AFTER a search, you retrieve a compressed FITS version of an image, and if you are using Netscape Navigator, the browser may remove the ".gz" extension to the FITS image filename -- but the file may still be in "gzip" format. In this case, you may either Add the ".gz" extension to the filename after you have retrieved it, then "gunzip" the file as usual; or Modify your Navigator "Options" to avoid the problem altogether, then retrieve the image again. See the <"Help" file> on this page for details.