1. It’s not the energy, it’s the entropy Saturn’s age is revealed in its moons Earth’s water source is not in the meteorite collections... Is the Hadean Earth unavoidably anomalous? Methane vs. water cycles. We’ve already found martian life The best system to visit isn’t Jupiter’s The sky’s the limit The budget’s the limit

2. Interstellar Matter and Chemistry

4. C,H,O,N,P... Amino acids Nucleotides Proteins DNA, RNA Elements MonomersPolymers Carbon is the scaffolding and water is the liquid medium. LIFE AS WE KNOW IT......

5. The cycle of matter in the present epoch 1. Nucleosynthesis of heavy elements 2. Formation of molecules in the interstellar medium 3. Grains form and reform --silicate and carbonaceous--in various environments J =1→0 line emission for CO in the Milky Way. Courtesy L. Ziurys

6. The cycle of matter in the present epoch (cont.) 4. Chemistry (gas, surface) in a wide variety of environments in the interstellar medium i.Diffuse interstellar medium--PAH’s ii.Cold, dense clouds--water ice, CO, surface chem iii. Warm clouds/hot cores--CO, H 2 CO CH 3 OH 5. Disk formation and chemistry i.Chemistry during infall ii.Thermal chemistry in the disk. iii.Chemistry in subdisks around giant planets CO→ CH 4 Planetary atmosphere chemistry Expulsion of atmosphere and cometary material during red giant phase.

7. ISO-SWS

8. Over 120 found in interstellar space

12. Over 70 amino acids have been found in the Murchison meteorite, most of which are not used in terrestrial biology

13. The generation of complexity

14. Development of molecules, minerals, polymers...and life

15. The three laws of thermodynamics 1.Energy can be transformed but is conserved 2.Any process increases the overall entropy 3.The entropy can get arbitrarily small at arbitrarily low temperatures.

16. Lineweaver

17. Diluted Sunlight represented here by reflected spectrum Thermalized sunlight Sun

18. S = k log e (N states ) ΔS > 0  ν m declines Maximum entropy  thermodynamic eq. ν ν ν ν ν ν ν ν ν ν Planetar y surface E=Nhν

19. Dilution of photon stream after expansion through free space ΔS = 0 Interaction with matter on the planetary surface ΔS > 0 Sun

20. Dilution of photon stream after expansion through free space ΔS = 0 Interaction with matter on the planetary surface ΔS > 0 Absorption of 1% of sunlight in photosynthesis ΔS > 0 Sun

21. “Stars In your multitudes Scarce to be counted Filling the darkness With order and light” Les Miserables Lineweaver

22. McCabe and Lucas

23. Propositions 1. The expansion of the universe is the key global feature of the cosmos making life possible 2. The Sun’s low entropy, not its large energy, is the key local feature making life on Earth possible. 3. It took a long time for the party to get going on the Earth: we are (sadly, gladly) alone. 3. How long the party will go on depends on nature and strength of dark energy (Darth Vader or caped crusader?)