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SOFIA - Planetary System “Awesome” Science Science Vision off-site meeting, June 6, 2008 OUTLINE: Panel membership Approximate panel schedule Planetary science categories Some science examples - solar system - planetary system formation - exoplanets Planetary System Science Panel Jeff Cuzzi (lead): planetary rings and moons, planetary formation Dana Backman (deputy): planet and star formation [provide main panel connection to the project; answer “feasibility” questions] Athena Coustenis: Titan Dale Cruikshank and Josh Emery: primitive bodies: asteroids, Centaurs, Trans-Neptunian Objects, Kuiper Belt Objects, etc. Bob Haberle, Jeff Hollingsworth: Terrestrial planet atmospheres Mark Marley: exoplanets Mike Mumma: comets Glenn Orton: gas giant planets (Joan Najita: circumstellar disks; Ted Dunham: internal reviewer) Science Vision - Planetary Science Panel General Plan: Review of past work Augmentation of past work Identification of “awesome” science subset Writeup Planetary System Science Schedule May 20: kickoff telecon June: get updated write-up from AAS group (Black) get final Vision 2020 document (Young) get updated DRM cases (several) July: several more telecons and off-line coordination August: Bulk of writing August 29: First version for internal review Goal: 10 pages including figures; 3-5 major topics October 1: Receive final guidance from reviewers and SOFIA project October 8: Final draft October 8-23: zone of avoidance (DPS, Cassini PSG, other travel) (except, possible presentation to SOFIA workshop at the DPS) October 24: presentation for Blue Ribbon Panel SOFIA - Special Planetary Capabilities Can image the Jovian planets and their nearby moons - @ wavelengths of their peak continuum emission - @ wavelengths of organic molecular lines Can point at r < 1 AU - Venus and Mercury - Comets most active Can go anywhere on Earth to reach occultation shadows of solar system objects SOFIA - Planetary System “Awesome” Science Gas & Ice giant planets and moons: * water abundance, H/He ratio, D/H ratio, isotopic abundances [how did the solar system form?] * thermal properties (spatial and temporal variations, tidal heating) [how did the giant planets form? which moons may have oceans?] * occultations of Uranus, Neptune ring systems Primitive Bodies: comets, centaurs, TNOs, asteroids maybe only the brightest of the TNOs directly accessible others: diversity requires population studies * occultations (sizes & densities, atmospheres, companions) [how did the solar system form? did the giant planets migrate?] * spectroscopy (water, volatiles, organics, minerals, crystallinity, D/H) [how did the solar system form? how abundant are biology precursors?] SOFIA - Planetary System “Awesome” Science, cont’ Planet Formation: chemistry in Terrestrial zones [how do our solar system’s properties, especially astrobiology aspects, fit in relative to planetary systems forming now?] Exoplanets: transit detection(?) and spectroscopy; HST-like sensitivity [significance of “hot Jupiters” in relation to uniqueness, or not, of our solar system’s architecture] SOFIA - Planetary System “Awesome” Science, cont’ Mars atmospheric evolution, dynamics: * water cycle …? * biogenic methane ? (large-scale spatial variations) [does life exist on Mars, or did life exist there once?] Titan atmosphere composition (and dynamics?) [big organics factory; low-temperature analog to pre-life Earth] Inner solar system: * Mercury sodium [how did Mercury form? properties don’t fit condensation sequence…] * Venus’s deuterium abundance, evidence for a vanished ocean [Earth’s twin gone bad?] Solar System Objectives (from 2006 HQ Roadmap) • • • • • How did the Sun’s family of planets & minor bodies originate? How did the Solar System evolve to its current diverse state? What SS characteristics led to the origin of life? How did life begin & evolve on Earth; has it evolved elsewhere in the SS? What hazards & resources of SS will affect extension of human presence in space? Augmented objectives given breakdown of other groups • • • • How do planetary systems form in their parent protoplanetary disks? How do extrasolar planetary systems evolve to their current diverse state? What planetary system characteristics may lead to the origin of life? What do brown dwarfs tell us about the planet formation process? Assertions • • • • • “Awesome” Science will be done on important, far-reaching clusters of problems where SOFIA’s combination of sensitivity, spectral coverage, spectral resolution, long program duration, and spatial mobility and flexibility are critical SOFIA will not be competitive in areas where photometric stability, or high sensitivity and low noise, are critical. If we were the SOFIA TAC, what are the N (10?) most important scientific problems we would assign all its (solar system and exoplanet) time to? These will probably be object-centered but should be clearly related to high-level science objectives. “Other good science” can be noted, i.e. in an Appendix. Avoid “preaching to the choir” tone; document will be read by nonadvocates Issues • 1st (1-30) and 2nd (40-600) generation instruments; how real is, and when do we get the 2nd generation? Could “Awesome” Science rely partly on gen-2? Comets - 2020 package by Woodward mineralogy Fayalite Fe2SiO4 Access to water vapor spectral features Mobility allows observation from both hemispheres Low elevation range allows low solar elongation Large aperture allows observation of distant comets Spatial resolution Proximity < 82deg to sun Ortho-para ratio gives formation temp Forsterite Mg2SiO4 Woodward; from Koike et al 2003 Diversity of primitive bodies Lisse et al Spitzer Warm era Spectroscopy (composition) Occultations (size, density, atmosphere) Gas and Ice giants GREAT capability Temporal variability Isotope abundances Time Variations? Occultations at many latitudes/longitudes/times? Mid- and Far-IR spectral line sounding will determine H/He ratio (i.e. He mixing ratio) and vertical temperature profiles D/H ratio can be determined from FIR rotational transitions of HD Jupiter’s moon Io Saturn’s moon Enceladus Mars (and Titan?) meteorology • German interest in far-IR heterodyne spectroscopy for planetary science. • Atmospheric sounding by line profile inversion. • Line profiles depend on temperature, pressure, and mixing ratio. Wavelength?? • Vertical temperature and mixing ratio profiles can be retrieved from high S/N line profiles. Mars: zonal winds from 162 CO2 line Doppler Mars (and Titan?) meteorology Temp Profile Retrieval Wavelength?? Water Vapor Profile Retrieval Titan model with and without propane Exoplanets HD 209458 artist’s concept (left) and HST STIS data (below) Transits of a planet and its rarefied exosphere: Atmospheric composition and structure Atmospheric chemistry FLITECAM tuneable narrowband filters HIPO Tinetti et al 2007 Na? HD189733b HD209458b Exoplanet size, density, structure, atmospheric structure and composition (?) CH4 Without clouds With clouds Burroughs Protoplanetary Disks - gas EXES on SOFIA can resolve line profiles of emission arising from warmer inner (<~10AU) parts of the disk, constraining the gas mass and morphology. Some lines expected are H2 (28 µm), S I (25 µm), and Fe II (26 µm). Also H2O, CH4, and CO should be detectable, and possibly HCN and C2H2. (and SiO?) Carr, Najita, Salyk et al use narrow lines in several different spectral regions to characterize nebula opacity sources and the redistribution of solids. Future work may include isotopic abundances. Sensitivity maybe an issue. Possible second generation instrument? 28µm 17 µm 12 µm Protoplanetary Disks - solids Crystallinity? Fe/Mg ratio? Transport?