This image, made using a laser mapping technology called LIDAR, was taken on September 17, 2001. It shows a 3-D model of the rubble left behind in lower Manhattan following the attacks on the World Trade Center.
Minnesota Public Radio's Paul Tosto has a really interesting peek into the way mapping techniques like LIDAR were used to help rescuers and clean-up crew understand the extent of the damage, look for survivors, and rehabilitate the area around the disaster zone.
The Library of Congress work also includes data from a a thermal sensor flown at 5,000 feet over Ground Zero that provided images to track underground fires that burned for weeks at the site.
It's worth remembering that Google Earth didn't exist back then. The ancient science of cartography has been reborn with the technology of the last decade. Let's hope it's not called on again to map destruction.
Via Peter Aldhous