Transcript Planetary System “Awesome” Science

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? what was the “big bang” density?]
* thermal properties (spatial and temporal variations, tidal heating)
[how did the giant planets form? which moons may have oceans?]
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)
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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
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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
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“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
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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?
HD209458b
Exoplanet size, density, structure,
atmospheric structure and composition
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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?