Global mapping of greenhouse gases and air pollutants

Man must rise above the earth, to the top of the clouds and beyond, for only thus will he fully understand the world in which he lives, Socrates (470-399 B.C.) observed. Two and a half millennia later satellites orbiting the earth duly obliged, taking images spectrally resolved of the earth atmosphere in order to gain a better understanding of ozone chemistry, air pollution and of climate change. SCIAMACHY (Scanning Imaging Absorption spectroMeter for Atmospheric CHartograghY) fighting light and shadow in Greek mythology, is an optical spectrometer [1,2,3 and see Box 1] developed by German, Dutch and Belgian scientists and industry as a contribution in kind to ENVISAT, Europe's biggest satellite (see Box 2). Launched on March 1st 2002 by a European Ariane-5 rocket, it has since completed nearly 30.000 orbits around the earth, producing more than 35 million measurement scenes. Its projected 5 year lifetime has now passed. Time to take stock.