1. Lecture V: Terrestrial Planets & Summary 1.Plate Tectonics 2.Atmospheres & Spectra 3.Geophysical Cycles 4.Future Exploration

2. Earth’s tectonic plates today

3. Plate tectonics

4. Super-Earth Model Input: M, P surf, T surf, guess R, g surf, composition Output: R, ρ(r), P(r), g(r), m(r), phase transitions, D,...

5. Plate tectonics on Super-Earths Plate tectonics - more robust for higher masses: < Thinner plates, stronger stress (Valencia, O’Connell, Sasselov 2007)

6. Super-Earths geochemistry, e.g. the Carbonate-silicate cycle, or Sulfur cycle, etc. Planets of different initial conditions are “driven” to a set of geochemical equilibria by global geo-cycles over geological timescales. e.g., Halevy & Schrag (2008)

7. Atmospheres: A hot Jupiter (51 Peg b) spectrum Seager & Sasselov (2000)

8. Photometric Light Curves Micromagnitude variability from planet phase changes Space-based: MOST (2005), COROT (2007), Kepler (~2009)  m=2.5 (R p /D) 2 2/3/  (sin(  ) + (  -  )cos(  ))

9. Scattered Light Need to consider: phase function multiple scattering

10. Scattering Phase Functions and Polar Plots Seager, Whitney, & Sasselov 2000 Forward throwing & “glory” MgSiO 3 (solid), Al 2 O 3 (dashed), and Fe(s)

11. Scattered Light Changes with Phase Seager, Whitney, & Sasselov 2000 51 Peg @ 550 nm

12. Atmosphere: What is special about atomic Na and the alkali metals? Seager & Sasselov (2000)

13. Atmosphere: The tricks of transmission spectroscopy: Brown (2001)

14. Atmosphere: Theoretical Transmission Spectra of HD 209458 b Wavelength (nm) Occulted Area (%) Seager & Sasselov (2000)

15. Direct Detection of Thermal Emission

16. Transit & eclipse of HD189733b Heather Knutson & Dave Charbonneau (2007)

17. Spectra Four observed data points vs. models Burrows, Sudarsky, & Hubeny (2006)

18. Spectrum for HD 189733b Obtained by transit transmission & eclipse emission Wavelength Inverse Residual Flux

19. New 2  m Spectrum for HD 189733b (Swain et al. 2008)

20. The “Tree of super-Earths” Super-Earths Mini-Neptunes Ocean Planets / Water Planets Terrestrial Planets / Dry, Rocky Planets Fe -rich mantle ? H 2 O -rich mantle ? ? ? ? (Sasselov, 2008, Nantes)

21. Theoretical spectra of Super-Earths How to distinguish mini-Neptune from super-Earth: < Three types of atmospheres (Miller-Ricci, Seager, Sasselov 2008)