Keyhole makes spy satellite photos available, and distributes an elegant viewer program to allow you to “fly” around the world and zoom in to see details. The resolution varies depending on the satellite photo that was used. At its best you can clearly see cars and trucks. I played with this on a rainy Sunday afternoon, for hours. It is compelling.

Zoom in on your favorite atomic energy plant. See the twin plumes of steam from the cooling towers on the left. You can clearly see the twin reactors. There is a disused third reactor at the bottom of the picture, with its domed containment. building.

This imagery would have its uses for anyone working with or studying land-use patterns and urban sprawl to name only two ideas.

There is an active user community that creates new overlays and interprets existing data. Someone has found all the campsites along the Apalachian Trail. Someone has found all the U.S. atomic plants. Someone found a Concorde sitting on the tarmac in Toulouse. There is an overlay of air pollution hot spots, which can be shown on any portion of the world to create a gobal polution map.

The flyovers are amazing, and you can change your angle of perspective so that you aren’t directly over an area but appear to be flying to it. They acquire updated imagery on a regular basis.

After playing with this for several hours, a couple of questions and ideas come to mind.

• What are the ways that ordinary citizens can use this information to document environmental problems? For example, could it be used to docuement clear-cutting of forests, or water pollution?
• How can this application be misused? Is it helpful to terrorists?
• If what we’re seeing is this good, presumably the military/intelligence versions of these images are orders of magnitudes better. Can they tell whether my shoes are untied from 150 miles up?