English: The first bistatic radar image acquired by the twin satellites TanDEM-X and TerraSAR-X shows the Italian volcano Mount Etna, on the east coast of Sicily. On the left of the image, below the flank of the volcano, the city of Catania can be seen as a collection of bright points. This image, acquired while the satellites were orbiting at a distance of only 350 metres from one another, is the world's first to be made using such a close satellite formation.