For almost 2,000 years, the River Thames has served as the life force of London, capital of the United Kingdom and one of the world's most famous cities. In AD 43 the Romans established the trading settlement of Londinium at a favorable crossing point on the river. The Romans remained until the 5th century, when the city came under Saxon control. The early 17th century saw enormous growth, but the deadly plague of 1664 and 1665 ravaged the population, and in the following year the Great Fire, which burned for four days, destroyed most of the city. A public transportation system and other city services in the early 19th century eased many of the increasing urban problems of the burgeoning capital of the wealthy British Empire. After coping with the devastating effects of bombing during World War II and the gradual dismantling of the empire, London today thrives as a vital modern metropolis. London is one of 100 cities being studied using ASTER data to map and monitor urban use patterns and growth.

This image was acquired on October 12, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA's Earth Science Enterprise, a long- term research effort to understand and protect our home planet. Through the study of Earth, NASA will help to provide sound science to policy and economic decision-makers so as to better life here, while developing the technologies needed to explore the universe and search for life beyond our home planet.

Size: 39.5 x 55.3 km (24.5 x 34.3 miles)
Location: 51.5 deg. North lat., 0.1 deg. West long.
Orientation: North at top
Image Data: ASTER bands 1,2, and 3.
Original Data Resolution: 15 m
Date Acquired: October 12, 2001