1. astrochem.org the astrochemistry lab at NASA Ames Research Center (image by Andy Christie for Scientific American July 99)

2. The search for life in the Solar System: We may get lucky… Image of Europa from ase.jpl.nasa.gov/

3. Amino acids Sugars Nucleobases Nitrogen containing heterocycles Substituted aromatics …but the search for life in the Solar System is far more likely to be the search for organic biomarkers Fatty acids

4. Molecules that look like biomarkers (but may not be convincing indicators of life) 1.Various aromatics (invoked in martian meteorite) 2.Amino acids (components of proteins) 3.Fatty acids (components of membranes) 4.Sweeping generalizations

8. We make a little bit of space in our laboratory, and see what happens.

9. Interstellar ice photochemistry (image by Andy Christie for Scientific American July 99)

11. High ee Only one (or a very narrow distribution of) chain lengths or functional groups when many are expected. No more free molecular species, commonly used in geochemistry i.e., terpenes or PAHs Unless…you see something way out of equilibrium or non sensical i.e., Drawing a line in the (Martian) sand

12. Definitely: No enzymatic tests that rely on their biochemistry being the same as ours. Don’t assume their chromophores will be the same as ours i.e., Chlorophyll

13. Keeping an open mind On the other hand, we don’t want to miss life because its basic components are different from ours. Would we get a detection if they used different bases, different sugars, and had the opposite chirality of amino acids?

14. Knowledgeable & open-minded without being credulous In summary we must be

15. SETI Knowledgeable & open-minded without being credulous Jason Dworkin (GSFC), Scott Sandford, & Louis Allamandola (Ames) In summary we must be much like the Astrobiology & Exobiology panels to whom I am grateful for financial support

18. XA Liu et al., Science (2003) 302, 868.

20. XT

22. Eschenmoser (1999) Science, 284, 2118 Alternative sugars, i.e., allopyranose

23. HO 3 P-

25. FMN, coenzyme in certain oxidation- reduction reactions in the body

26. chirality (almost) All the chiral amino acids in living things are left handed, and there is also a bias for left handed amino acids in meteorites. The reason(s) for this is not yet clear. (non-super imposable mirror images) Cronin, J. R., & Pizzarello, S. (1997) Science 275, 951-955.