The Stratospheric Observatory for Infrared Astronomy (SOFIA), the world’s largest mobile observatory, made a rare stop on the US East Coast in September. This photo, taken at Joint Base Andrews in Maryland, shows the outside of the German-made 2.5-meter telescope, which is housed in a Boeing 747 flown by NASA. The telescope is equipped with an IR spectrometer known as the German Receiver for Astronomy at Terahertz (GREAT), built by a research collaboration that included the University of Cologne and the Max Planck Institute for Radio Astronomy.
Cruising at an altitude of 40 000 feet (12 200 meters), SOFIA flies above 99% of atmospheric water vapor, which gives it access to IR wavelengths that are blocked from ground-based IR telescopes, says Paul Hertz, chief scientist at NASA’s science directorate. Based at NASA’s Dryden Flight Research Center in California, SOFIA typically flies for 10 hours, including the two hours required for...
