ISS013-E-78295 Click the photo number to access all resolutions available and the database record.
The Po River, Italy’s longest river, runs approximately 650 kilometers (400 miles) from the southwestern Alps to the Adriatic Sea, passing indirectly through Milan, and through Turin. As Turin is an industrial center of a heavily urbanized region, pollutants often cloud the skies overhead. In fact, northern Italy is one of Europe’s pollution hotspots, and the smog often grows thick enough to be seen from space. Smog in this area is so persistent that astronauts on the International Space Station have photographed other images of it, in October 1997 and February 2003. Recurring accumulations of smog in the Po River Valley, however, result from more than just the industrial emissions from the area around Turin. In this area, smog is often trapped at the base of the Alps by high atmospheric pressure.
