Over the sixty years of the Space Age, remote sensing from the air and space has developed into an amazing tool. Originally driven by military necessity, remote sensing from space has revolutionized Earth Science as well as planetary science in the whole solar system. There simply would be no arguments about climate change if not for terabytes of satellite data clearly and irrefutably showing world wide trends.
Airborne and satellite measurements have also begun to revolutionize archaeology. Remote sensing can see through jungle and sand, and cover thousands of kilometers with centimeter resolution. It not lonely helps find where to dig, it gives an essential bigger picture to understand what has been dug up.
This summer Pola Lem discussed the history of space archaeology, Beginning with declassified images from spy satellites, imagery from the US Space Shuttle and now an ever growing fleet of Earth Observing satellites from many nations, archaeologists can explore areas of interest “from their desk” before rolling the dice on an expensive, dangerous, and time consuming excavation.
Lem recounts the 1985 observations of the Omani desert from the Space Shuttle. Based on historical guesswork, the radar imagery detected evidence to locate the ancient oasis and city of Ubar. This is the first recorded instances of space imagery being used specifically for archaeology.
‘Okay, let me get this straight: You want to use my spaceship to find your lost city?’
Even more important is the development of LIDAR (light detection and ranging) deployed on aircraft and nowadays on UAVs. Lidar can generate extremely precise elevation maps which reveal buried structures or ancient landscapes. (Lidar is also one of the key technologies for intelligent and self-driving vehicles.) Lidar is especially useful for seeing through jungle foliage, and has led to discovery of vast new evidence about pre-Colombian Mesoamerica.
In a rather Karmic cycle, archaeology is threatened by the data they thrive upon. Space Archaeology was born from public release of declassified military secrets, and now many archaeologies try to keep their satellite imagery secret to protect the sites from looters. (This is unlikely to work for long—it is easy to get remote sensing data.) Archaeologists now seeks to use remote sensing to protect ancient sites from tourism and looting.
- Pola Lem, Peering through the Sands of Time: Searching for the Origins of Space Archaeology, in The Earth Observatory – Features. 2017, NASA. https://earthobservatory.nasa.gov/Features/SpaceArchaeology/