1 assembling the puzzle from earths to super-earths hitran to the rescue... “ good planets are...
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Assembling the puzzle
From Earths to Super-EarthsHitran to the rescue...
“Good planets are hard to find” Bracewell
Lisa KalteneggerHarvard-Smithsonian Center for Astrophysics
HITRAN Conf, June 22th 2008
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Planets... The story so far...
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New worlds in our sky... 300+shadows of weird worlds...
What can we tell?
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The KEY... Transiting planets
Torres 2008
Fortney, 2007Sasselov 2007
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Weather forecast on Giant exoplanets? Atmosphere by transits... HD189733b
Tinetti et al 2007
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WHY ?
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The Pale Blue Dot
Voyager image, 400 billion km away
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Earth IR-emission
TES data; Christensen 2004
Kaltenegger, Traub, Jucks 2007 (ApJ)
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Line of Evidence
WHAT KIND
INTERIOR
ATMOSPHERE
LIFE ?
Density ?(radius/mass)
Plate tectonics?Ocean/land?
What chemistry?What star ? HZ ?
What biota?
FORMATION Formation Models
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Line of Evidence
FIND
INTERIOR
ATMOSPHERE
LIFE ?
SPECTRAL FINGERPRINT
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add
OUTLINE CODES
• Climate (Kasting, Segura, Pavlov)
• Photochemistry (Segura, Kasting)
• Radiative Transfer (Traub, Jucks)
Planet interior & outgassing
Cloud physics (CO2 & H2O)add
Kaltenegger et al 2007
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Signs Of Life On An Earth-like Planet
Vegetation
Plantproduct
Plant life
Bacteria
observed
WaterOxygen
Carbondioxide
Methane Nitrousoxide
Ozone
Needed for life Primordial;
& bacteria product
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Selsis 2007
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Spectral features IR & Is there Take out ?
Traub & Jucks, AGU, 2002; Des Marais et al. 2002, Selsis 2003, Kaltenegger 2007
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Atmosphericescape
OutgassingEarly or continuous
Geochemical recyclinge. g. carbonate silicate cycle
Biological processing
photochemistry
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LIFE
LIFE
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Selsis (data Kasting et al 93)Update Kaltenegger & Segura (prep)
The Test...The possibilities...Characterizing planets
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Habitable Zone... Goldilocks Zone
Selsis, Kasting et al 2007; Kaltenegger & Selsis 2007
19Paillet et al., in prep
TPF-CNew World Finder
CIS for Exoplanets: Spectral Fingerprints
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Earth part of the puzzle...
& a universe full of possibilitiesSontin et al 2007Leger et al 2004
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How to make water from a H2-rich atmosphere ?
Reduction of Fe-bearing silicates by H2 (Sasaki, 1990)
For fO2 ≤ core formation
H20/H2 ~ 0.1(Solar nebula : 6 x 10-4 Delivery?)
H2O vapor promotes greenhouse: Earth’s temp. as high as 4800 K
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Earth Evolution over geological time
Kaltenegger et al 2007 ApJ
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Continuous habitable zone
Goldilocks ZoneGl 581c... HOT, Gl581d COLD
Selsis et al 2007, Kaltenegger et al 2008, Seager et al 2008, Miller-Ricci et al 2008,...
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Super Earth around M star 3400K
Tidally locked planet1: day (60%) night side (40%)
2: day (75%) night side (25%)
3: day (85%) night side (15%)
Kaltenegger et al 2008 (in prep)
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Super Earth around M star 3400KTidally locked planet (rapidely rotating planet comparison line (shown in grey))• Scenario 3: high heat transport from day (85%) to night side (15%)
Kaltenegger et al 2008 (in prep)
CO2
O3
CH4H2O
H2O
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Transits... Pushing the limits
Kaltenegger, Traub, Jucks 2008 (sub)
Radius +/- ~ 0.06%
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Transits... Detecting habitable atmospheres
Kaltenegger, Traub, Jucks 2008 (sub)
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Hitran Shopping list• Near-IR lines (CH4)• Line profile (especially wings - Transits)• Self broadening... Line broadening • High atm pressure (< 3 bar)
– (= high gravity on Super-Earths)
• Transits probe upper Earth atmosphere mainly• Warming and cooling of atmosphere
– e.g. dense and early Earth atmospheres– …
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LIFE
LIFE
LIFE
SUPER EARTHS...
opportunity & challenge
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Habitabitity of Super Earths Gl581dGl 581d: Earth Amtosphere, 2.63 bar, 1.8x Earth gravity. M star 3200KScenario 1: no heat transfer day & night side (freeze out on dark side)Scenario 2: Planet rapidely rotating like Earth (same temperature day and night side)Scenario 3: Low heat transfer between day (75%) & night side (25%), no freeze out
Kaltenegger et al. 2008 (in prep)