Images: Satellite images help detect Mayan ruins

In a side-by-side comparison, space-based images captured by two commercial Earth-observation satellites--the Landsat TM, left, and the IKONOS--focus on the ancient ruins of Tikal, a Mayan city deep in the Guatemalan rain forest. The Landsat imaging system has a nominal resolution of 30 meters, while the IKONOS can capture a nominal resolution as close as 1 meter, a scale at which individual pyramids, pathways and small structures become apparent. Both use false-color imaging--depicting subjects in colors that differ from human perception--to help NASA and university scientists study patterns of jungle growth and floral discoloration that is enabling discovery of Maya ruins lost for more than 1,000 years.

Ever-improving optics, imaging and satellite technologies play a key role in enabling scientists to conduct increasingly sophisticated Earth science activities around the world.