ANDRE Mueller is a virtual explorer of virgin territory.
One morning, off the southwest coast of Iceland, the 25-year-old German physics student noticed a wispy line -- a wrinkle, almost -- in the elaborate patchwork of satellite imagery that makes up Google Earth.
He zoomed in for a closer look.
It was smoke.
At the end of the trail, he discovered what appeared to be three boats. He slapped a "placemark," the program's version of an explorer's flag, on the location and reported his findings on the Google Earth Community bulletin board.
"What are these three ships doing there?" wrote Mueller, using the handle earthling_andre. "And why is there so much smoke?"
His fellow office-chair detectives showered him with praise for the discovery ("Now that's an AMAZING FIND," one replied), then went to work trying to solve the mystery of the burning ship.
Google Earth is packed with things that its creators never intended. Paper maps are a cartographer's rendering of the world, whereas digital versions in Google Earth, Google Maps and Microsoft's Live Search Maps are more like sophisticated collages -- moments captured by cameras on satellites and airplanes, seamlessly blended to create a digital world.
If inspected very closely, these photos from on high sometimes reveal life going on when the shutter opened and closed: airplanes in flight, surfers off Malibu, mourners congregating in a Chicago cemetery, a Boston Red Sox game underway at Fenway Park, a cement truck overturned in San Francisco.
"These are life's moments that are unexpectedly caught from above," said Jason Lee, 30, a Bellingham, Wash., marketer. He and computer programmer Jon Coogan run Bird's Eye Tourist, a website that compiles things of interest submitted by users of a Live Search Maps feature known as bird's eye view.
What may appear as a blemish to digital mapmakers is becoming sport for virtual discoverers. The hunt is on to find and share those moments.
The Google Earth Community and independent enthusiast sites such as Google Earth Blog, Google Sightseeing and Bird's Eye Tourist serve as repositories for these finds, where people can discuss, for example, a submarine captured in a permanent state of departure from Tokyo Bay (the bow-wake characteristics and sail-to-rudder measurement suggest it is a Yushio class sub, a Google Earth Community veteran concluded).
John Hanke, director of Google Earth and Maps, said the hunt for interesting things reminded him of the Web's early days, before search engines and directories.
"There's a huge amount of undiscovered territory out there for these geo-explorers to go and explore," he said.
Unlike famous explorers such as Capt. James Cook, these virtual voyagers can scour the globe with little physical effort or danger. Google Earth covers about 30% of the world's land surface with high-resolution imagery. That's a lot of ground to cover.
Mueller, the physics student, is an amateur astronomer and map buff. On July 26, 2005, as he sat at home in Aachen, Germany, he brewed some coffee and turned his attention to what he calls the "next-generation atlas" on his laptop.
First he activated a Google Earth feature that displays, as dots on the map, everything the program's users had ever tagged as noteworthy. He then focused on the empty spots still covered by high-resolution satellite photos. By chance, he spotted the smoke trail leading to the ship in only minutes, about seven nautical miles off the coast of Iceland's Reykjanes peninsula.
The first reply to his posting came nine minutes later. "That scene does not look good at all," a visitor wrote on the community's bulletin board, noting the presence of another ship that appeared to be racing to help. Another member pointed out yet another ship, heading back to shore.
Seven responses were posted in the first two days. One sleuth pinpointed the fire's date; he activated a feature revealing that DigitalGlobe, the company that provides most of Google Earth's satellite images, had shot the photo almost a year earlier, on Aug. 11, 2004.
But then the trail went cold, and the message board silent, for three weeks. Mueller thought that the answer would never come. It turns out Mueller just needed to find the right people in Iceland.
"On my own I could never find out what exactly I saw," Mueller said. "But in the global village there is someone, somewhere, speaking Icelandic who knows just where to look in the right newspaper archive for details."
PROGRAMS that compile satellite imagery into maps have long existed, but the expensive price tag left them the playground of government officials, academic researchers and real estate developers.