Courtesy NASA

In what is being touted as the Internet’s largest digital image
ever, two software engineers have posted an ultra-high-resolution
picture of the Earth’s surface as a demo of their high-res-image-serving software. The 3.7-gigapixel image—weighing in at approximately 10.7 gigabytes—is taken from NASA’s Blue Marble
program, which uses Earth-imaging satellites to extensively photograph
and study the planet. The software, which was originally commissioned
by London's National Gallery to serve zoomable large-scale images of
artwork over the Web, divides the main image into thousands of smaller
mosaic tiles and serves them as needed depending on the location and
zoom level relative to the original image. The system is also used to
display images from the Hubble telescope, which can be zoomed in on to
reveal ridiculous levels of detail.

It’s amazing to think that for all but a fraction of world history,
no one knew what the planet Earth looked like from space. And now, a
detailed satellite view of practically every inch of the planet—previously
available only to privileged government agencies—is accessible to
anyone through the Web. —John Mahoney