Environmental satellites

Four Landsat satellites (launched in 1972, 1975, 1978, and 1982) were specifically designed to learn about how all the parts of the planet interact. Three are still sending back data. The newest generation of environmental satellites are part of a National Aeronautic and Space Administration (NASA) initiative that aims its space instruments at the Earth instead of at the stars.

This program, called Mission to Planet Earth, may well take precedence over space exploration for the next few years. Its Earth Observing System (EOS) will include 19 new satellites to be launched over the next 15 years. "The idea grew out of a critical mass of scientists coming together to understand how the Earth as a system is changing," explains Robert Price, director of the Mission to Planet Earth Office for NASA. "If humankind is changing the face of the Earth, it's time we started answering some of the scientific questions relating to that."EOS focuses on the remote sensing of climate change indicators such as the ozone layer in the upper atmosphere, cloud cover, and sea-ice at the poles. In addition, it follows the climatological effects of localized phenomena like volcanic eruptions and El Niño, a periodic change in wind patterns and current movements that results in decreased fisheries along the southern Pacific coast. The information provided by EOS satellites will determine the course of environmental management in the future.