The European Space Agency's Envisat environmental satellite is constructing what will work out to be the most detailed image ever of our home planet.

Over the next two years, the Envisat's imaging spectrometer will take a series of 300 meter images of Earth's land surface area; when completed, the image will require 20 terabytes of storage.

The picture shown here is a mosaic from Envisat assembled from 1561 orbits taking place over May, July, October and November, 2004. Click it for a much larger version.