During the last 25 years, we have all become accustomed to seeing images of the Earth from satellites in the public media (newspapers, television and internet) and have become familiar with the fascination they create.
This fascination has two complimentary aspects:

• The panoramic and animated view of our planet offered by meteorological satellites, such as Meteosat, which enable the observation of the movements of air masses and clouds, and to some extent also, sea currents on a perpetually rotating Earth.
• Precise mappings of farmlands, factory plants, and buildings from satellite sensors designed for the observation of the Earth at high or very high spatial resolutions. These images are now accessible through 'geographic portals' such as Google Earth, but because of the low frequency of their orbital repeat cycle, cannot be updated frequently.

The year 2000 marked the beginning of a new generation of Earth observation systems, among which the most successful example is the Moderate-resolution Imaging Spectroradiometer (MODIS), aboard the Aqua and Terra satellites.
MODIS offers intermediate features that are between those of the two types of conventional satellite systems described above. It allows daily monitoring of the Earth, thereby highlighting environmental changes that occur on a weekly timescale.
The spatial resolution range (250 to 1000 m) was designed and adapted for the detection of natural phenomena on land (floods, forest fires) or sea (currents, primary production linked to photosynthesis), but it also helps to highlight the impacts of human activities on the environment, such as those due to agriculture, irrigation and urbanization, but also on a larger scale, deforestation and pollution.

The main scientific applications of the MODIS data products are related to environmental surveillance of the atmosphere, oceans, and biosphere. To contribute to this activity, the "Laboratoire d'Optique Atmospherique" (LOA) of the University of Science and Technology, Lille has developed a system for continuous acquisition and processing of MODIS imagery in a routine fashion, with all the required scientific rigor, taking advantage of our great experience in processing satellite data, particularly in the modeling and correction of atmospheric effects.
However, beyond the small community of scientific users, MODIS imagery can be a remarkable tool for environmental education and sustainable development, while providing a better visibility of the scientific activities of LOA. It is from this perspective that we have undertaken the realization of a Web site dedicated to the visualization, downloading, and analysis of MODIS imagery, with the collaboration of geographers from Lille University and Paris ENS, and other environmental scientists (geologists, biologists) who may be interested in this project.

The site is designed to educate a wide audience, including teachers, students, and the general public. It allows users to visualize, select, and download images that have been calibrated, with some of the atmospheric effects corrected, and geo-referenced using the most rigorous methods to satisfy mapping requirements.