1. 1 Assembling the puzzle From Earths to Super-Earths Hitran to the rescue... “ Good planets are hard to find ” Bracewell Lisa Kaltenegger Harvard-Smithsonian Center for Astrophysics HITRAN Conf, June 22th 2008

2. 2 Planets... The story so far...

3. 3 New worlds in our sky... 300+ shadows of weird worlds... What can we tell?

4. 4 The KEY... Transiting planets Torres 2008 Fortney, 2007 Sasselov 2007

5. 5 Weather forecast on Giant exoplanets? Atmosphere by transits... HD189733b Tinetti et al 2007

6. 6 WHY ?

7. 7 The Pale Blue Dot Voyager image, 400 billion km away

8. 8 Earth IR-emission TES data; Christensen 2004 Kaltenegger, Traub, Jucks 2007 (ApJ)

9. 9 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

10. 10 Line of Evidence FIND INTERIOR ATMOSPHERE LIFE ? SPECTRAL FINGERPRINT

11. 11 add OUTLINE CODES Climate (Kasting, Segura, Pavlov) Photochemistry (Segura, Kasting) Radiative Transfer (Traub, Jucks) Planet interior & outgassing Cloud physics (CO 2 & H 2 O) add Kaltenegger et al 2007

12. 12 Signs Of Life On An Earth-like Planet Vegetation Plant product Plant life Bacteria observed Water Oxygen Carbon dioxide Methane Nitrous oxide Ozone Needed for life Primordial; & bacteria product

13. 13 Selsis 2007

14. 14 Spectral features IR & Is there Take out ? Traub & Jucks, AGU, 2002; Des Marais et al. 2002, Selsis 2003, Kaltenegger 2007

15. 15 Atmospheric escape Outgassing Early or continuous Geochemical recycling e. g. carbonate silicate cycle Biological processing photochemistry

16. 16 LIFE

17. 17 Selsis (data Kasting et al 93) Update Kaltenegger & Segura (prep) The Test...The possibilities...Characterizing planets

18. 18 Habitable Zone... Goldilocks Zone Selsis, Kasting et al 2007; Kaltenegger & Selsis 2007

19. 19 Paillet et al., in prep TPF-C New World Finder CIS for Exoplanets: Spectral Fingerprints

20. 20 Earth part of the puzzle... & a universe full of possibilities Sontin et al 2007 Leger et al 2004

21. 21 How to make water from a H 2 -rich atmosphere ? Reduction of Fe-bearing silicates by H 2 (Sasaki, 1990) For f O 2 ≤ core formation H 2 0/H 2 ~ 0.1 (Solar nebula : 6 x 10 -4 Delivery?) H 2 O vapor promotes greenhouse: Earth’s temp. as high as 4800 K

22. 22 Earth Evolution over geological time Kaltenegger et al 2007 ApJ

23. 23 Continuous habitable zone Goldilocks Zone Gl 581c... HOT, Gl581d COLD Selsis et al 2007, Kaltenegger et al 2008, Seager et al 2008, Miller-Ricci et al 2008,...

24. 24 Super Earth around M star 3400K Tidally locked planet 1: day (60%) night side (40%) 2: day (75%) night side (25%) 3: day (85%) night side (15%) Kaltenegger et al 2008 (in prep)

25. 25 Super Earth around M star 3400K Tidally 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) CO 2 O3O3 CH 4 H2OH2O H2OH2O

26. 26

27. 27 Transits... Pushing the limits Kaltenegger, Traub, Jucks 2008 (sub) Radius +/- ~ 0.06%

28. 28 Transits... Detecting habitable atmospheres Kaltenegger, Traub, Jucks 2008 (sub)

29. 29 Hitran Shopping list Near-IR lines (CH 4 ) 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 –…

30. 30 LIFE SUPER EARTHS... opportunity & challenge

31. 31 Habitabitity of Super Earths Gl581d Gl 581d: Earth Amtosphere, 2.63 bar, 1.8x Earth gravity. M star 3200K Scenario 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)