Sarah Parcak believes that “today is the most exciting time in history to be an archaeologist”:
Space archaeology refers to the use of space- and air-based sensor systems to discover ancient settlements, cultural remains, and natural features (like relic river courses) otherwise invisible to the naked eye, or hidden due to vegetation and water. Archaeologists use datasets from NASA and commercial satellites, processing the information using various off-the-shelf computer programs. These datasets allow us to see beyond the visible part of the light spectrum into the near, middle, and far infrared. These spectral differences can show subtle differences in vegetation, soil, and geology which then can reveal hidden ancient features.
Satellite datasets like WorldView can see objects as small as 1.5 feet in diameter. In 2014, WorldView-3 will be able to see objects a small as a foot. Another important sensor system is LIDAR (which stands for Light Detection and Ranging). LIDAR uses lasers to scan terrain in fine detail and even penetrate dense rainforest canopy, allowing archaeologists to see beneath the trees to reveal features of interest, from large monuments to small, subtle remnants of ancient homes and road systems.
(Video: LIDAR in action at Stonehenge and surrounding areas)