Over 2,000 man-made satellites are currently orbiting the Earth, providing a wide range of services like communications, remote sensing, and global positioning. As more are launched and new technologies are developed, they will play an increasingly important role in everyday life. The Tech Museum offers this site (1) dedicated to the basics of satellites and their functions. A Java program...

The Earth Resources Observation Systems' Data Center of the US Geological Survey also maintains the Land Processes Distributed Active Archive Center to "process, archive, and distribute land-related data". The Center disseminates this data, collected by various satellite and aerial sensors, which include surface reflectances, land surface temperature, global geolocation angle, vegetation indices,...

NASA has unveiled its new Multi-Spectral Drought Indexer (MSDI), improving existing technology for measuring absorption and reflection of sunlight by plants in order to make maps of unprecedented detail. The data, which come from satellites, are translated by researchers into monthly maps of vegetation color changes, thus indicating how much soil moisture is available to plants. The existing...

As part of NOAA's National Environmental Satellite, Data, and Information Service, the Laboratory for Satellite Altimetry specializes in the analysis of satellite altimeter data related to problems in physical oceanography and marine geophysics. The Web site provides links to currently active projects with information such as near-real time sea level altimeter data, historical data, European Space...

In an effort to disseminate information from the TOPEX/ Poseidon satellite project, the Center for Space Research and the Texas Space Grant Consortium have developed the TOPEX/ Poseidon Kids Page. This online activity for younger students explains through simple descriptions and fun illustrations how the satellite measures the height of the ocean. Additional pages include an online quiz, a...

Satellites are used for just about any purpose imaginable, and the United Nations Institute for Training and Research Operational Satellite Applications Programme (UNITAR) is one that is meant to help out in "the life of communities exposed to poverty, hazards and risk." On their site, visitors should first take a look at the "What we do" area to learn about their recent achievements and work....