1. Synthesis of Molecules by Cosmic Ion Bombardment
M. H. Moore
NASA Goddard Space Flight Center
R. L. Hudson
Eckerd College
International Workshop Trans Neptunian Objects Dynamical and Physical Properties
July 2006

2. Outline Introduction-motivation for laboratory work
How we study ices in the laboratory
Review four cases
Predictions
Goal is to develop a good understanding of important volatile and less-volatile molecules relevant to TNO ice environments

3. Processes affecting original ices and dust in Proto-planetary Disks.
The composition of disk material is extremely sensitive to initial composition, nebular processing, and nebular dynamics.
mumma_

4. Original Interstellar Abundances > ½ IS organics are nitriles
Some Ice Environments
Original Interstellar Abundances
>100 known species
Largest has 13 atoms
> ½ IS organics are nitriles

5. Comparison of Cometary Volatiles with
Volatiles in Interstellar Environments
Underlined molecules identified also in condensed phase
aBased on Table 1, Ehrenfreund et al. Comets II, 2004
bFrom Table 1, Knez et al. ApJ 635, 2005 and Blake, private communication

6. Comparison of Cometary Volatiles with Ices in the Solar System
aBased on Table 1, Ehrenfreund et al. Comets II, 2004
bFrom Table 1, Knez et al. ApJ 635, 2005 and Blake, private communication

7. Radiation processes on KBO surfaces
Cosmic
Rays
MeV p+
~ K
UV Photons
Chemical
Reactions
Sputtering

8. Estimated radiation doses after 4.6 × 109 years a
a = Cooper et al., 2003

9. Schematic of laboratory set-up at NASA Goddard’s Cosmic Ice Laboratory

10. IR Spectrometer UV p+

11. Synthesis of Complex Organics
1. H2O + CH3OH
2. H2O + HCN
3. NH3 + HCN
4. N2 + CH4

12. Studies of ices rich in water are motivated by observations of TNOs
such as Quaoar and Charon

13. Ice studies with methane are motivated by observations of TNOs
such as Pluto and 2005 FY9

14. Case 1
H2O + CH3OH

15. 7%
12%
% carbon converted in
H2O + CO (5:1)
ice after 22 eV molecule−1
20%
40%

16. H2O + CH3OH (~3:1), T = 20 K
Hudson and Moore, Icarus, 145, 661 (2000)

17. Ethylene Glycol

18. Discovered in 2002 in the ISM & in Comet Hale-Bopp in 2004!
Ethylene Glycol
Discovered in 2002 in the ISM & in Comet Hale-Bopp in 2004!
(Hollis et al., 2000) (Crovisier et al., 2004)

19. Case 2
H2O +HCN

21. H2O + HCN (5:1), T= 20 K
Gerakines et al., Icarus, 170, 202 (2004)

22. Case 3
NH3 + HCN

23. 

24. Gerakines et al., Icarus, 170, 202 (2004)
NH3 + HCN (5:1), T = 20 K
CN -
dicyandiamide
H2CNH
NH3
NH3
HCN
NH4+
HCN
Gerakines et al., Icarus, 170, 202 (2004)

25. Case 4
N2 + CH4

26. C3H8
N2:CH4
Hudson and Moore Icarus, 172, 466 (2004)

29. 3.54 m Ethylene Glycol 2.16 m Hydrogen Peroxide Carbon Suboxide
Carbonic Acid
Ammonium Cyanate
Moore et al. Earth, Moon and Planets 92, 291 (2004)
Hudson and Moore, Astrobiology, 6, 483 (2006)

30. Reggie Hudson
Eckerd College
St Petersburg, Florida
Funding through NASA’s Planetary Atmospheres, Planetary Geology and Geophysics, Outer Planets, and

31. Univ. of Alabama at Birmingham
Thanks --- to collaborators
Perry Gerakines
Univ. of Alabama at Birmingham
Robert Ferrante
US Naval Academy

32. www-691.gsfc.nasa.gov/cosmic.ice.lab