SOFIA Takes Advantage of Mobility to Observe Pluto Occultation

A few hours before dawn on June 23, 2011, NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) flew more than 1,800 miles over the Pacific Ocean from its base in Southern California to a point where scientists observed the dwarf planet Pluto as it passed in front of a distant star. Known as an "occultation," researchers captured data that will enable them to make new measurements of Pluto's atmosphere and increase the knowledge base of this distant object.

SOFIA is a highly modified Boeing 747SP jetliner that conducts astronomy research not possible with ground-based telescopes. On behalf of NASA, USRA operates the SOFIA Science Center at NASA Ames Research Center, Moffett Field, Calif. Here, USRA researchers determine which celestial objects are best observed by SOFIA's 2.5-meter (100-inch) diameter telescope and its suite of seven purpose-built instruments, and pairs nearby objects into flight plans to enable the observatory to maximize its science flight time. Researchers also integrate newly developed instruments, and bring the observatory's science into the classroom and to the general public

"USRA's collaboration with NASA in developing, and now operating, SOFIA has been long and fruitful," said Dr. Fred Tarantino, USRA president. "Capturing the occultation of Pluto is an excellent demonstration of how well the NASA/USRA partnership works and showcases the dedication and determination of our staff and collaborators."

The Pluto occultation effort was led by principal investigator Ted Dunham of the Lowell Observatory in Flagstaff, Ariz., and closely coordinated with scientists from USRA and the Massachusetts Institute of Technology. Dunham is also the principal investigator of the High-Speed Imaging Photometer for Occultation (HIPO), essentially an extremely fast and accurate electronic light meter, used to monitor how the star's light reacted as it passed through Pluto's atmosphere.

Along with the HIPO research staff, a team of German scientists from the Deutsche SOFIA Institute at the University of Stuttgart flew on SOFIA to monitor the telescope's performance and image the occultation with the newly developed Fast Diagnostic Camera (FDC). For this flight, the FDC was operated as a photometer, generating a plot rather than a photograph of the event. Results from HIPO and the FDC will be analyzed and released in the coming months.

"SOFIA is at the beginning of its projected 20-year life span, and the Pluto occultation is the start of many interesting observations and discoveries to come," said Helen Hall, USRA's associate director of Program Management for SOFIA. "As an airborne telescope, SOFIA's biggest advantage is that we can configure the observatory with the right instrument to capture the best science possible. This provides a unique capability to astronomers the world over."

SOFIA is a joint program between NASA and the German Aerospace Agency (Deutsches Zentrum fur Luft- und Raumfahrt - DLR), Germany. The SOFIA program is managed by NASA's Dryden Flight Research Facility and the aircraft is based at the Dryden Aircraft Operations Facility in Palmdale, Calif. NASA's Ames Research Center, Moffett Field, Calif., manages the SOFIA science and mission operations in concert with the Universities Space Research Association (USRA), Columbia, Md., and the Deutsches SOFIA Institut (DSI), Stuttgart, Germany. For more information about SOFIA, visit http://www.nasa.gov/sofia . For information about SOFIA's science mission, visit http://www.sofia.usra.edu .

Founded in 1969, USRA is an independent research corporation with competencies that span space, Earth, and life sciences related disciplines, which are closely aligned with the nation's science and national security agencies. As a non-profit corporation with 105 major research university members, USRA's scientific and technical staff collaborate with over 300 universities annually. This depth of reach into the research community provides a unique platform for advancing science and technology.