It just became possible, thanks to a laser camera developed by physicists at Heriot Watt University in Edinburgh, UK. You can pretty much see how it works from the images above -- laser beams are bounced off the target and the duration of their return journey is measured precisely enough to detect millimeter depth changes even at extreme distances.

ENGADGET: Laser scans objects in 3D from half a mile away, scientists just need reason to use it