The Stratospheric Observatory for Infrared Astronomy - A New Tool for Planetary Science

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint US/German effort to fly a 2.5 meter telescope on a modified Boeing 747SP aircraft at stratospheric altitudes where the atmosphere is largely transparent at infrared wavelengths. Key goals of the observatory include understanding the formation of stars and planets; the origin and evolution of the interstellar medium; the star formation history of galaxies; and planetary science. SOFIA offers the convenient accessibility of a ground-based observatory coupled with performance advantages of a space-based telescope. SOFIA’s scientific instruments can be exchanged regularly for repairs, to accommodate changing scientific requirements, and to incorporate new technologies. SOFIA’s portability will enable specialized observations of transient and location-specific events such as stellar occultations of Trans-Neptunian Objects. Unlike many spaceborne observatories, SOFIA can observe bright planets and moons directly, and can observe objects closer to the sun than Earth, e.g. comets in their most active phase, and the planet Venus. SOFIA’s first generation instruments cover the spectral range of .3 to 240 microns and have been designed with planetary science in mind. The High-speed Imaging Photometer for Occultations (HIPO) is designed to measure occultations of stars by Kuiper Belt Objects, with SOFIA flying into the predicted shadows and timing the occultation ingress and egress to determine the size of the occulting body. HIPO will also enable transit observations of extrasolar planets. The Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) and the High-resolution Airborne Wideband Camera (HAWC) will enable mid-infrared and far-infrared (respectively) imaging with a wide range of filters for comets and giant planets, and colorimetric observations of small, unresolved bodies to measure the spectral energy distribution of their thermal emission. The German Receiver for Astronomy at Terahertz Frequencies (GREAT) will measure far-infrared and microwave spectral lines at km/s resolution to search for molecular species and achieve a significant improvement over current knowledge of abundance and distribution of water in planetary bodies. The Echelon Cross Echelle Spectrograph (EXES) and the Field Imaging Far Infrared Line Spectrometer (FIFI LS) will provide high-resolution spectral data between 5 and 210 microns to support mineralogical analysis of solar system and extrasolar debris disk dust and observe spectral features in planetary atmospheres. The First Light Infrared Test Experiment Camera (FLITECAM) will offer imaging and moderate resolution spectroscopy at wavelengths between 1 and 5 microns for observations of comets and asteroids, and can be used simultaneously with HIPO to characterize the atmosphere of transiting exoplanets. SOFIA’s first light flight occurred in May, 2010 and the first short science observing program is scheduled to begin in November, 2010. The Program will issue a call for new instrumentation proposals in the summer of 2011, as well as regular calls for observing proposals beginning in late summer 2011. SOFIA is expected to make ~120 science mission flights each year when fully operational in 2014.