Upload
fausto
View
39
Download
0
Embed Size (px)
DESCRIPTION
Cosmic Ice Laboratory Marla Moore Reggie Hudson Paul Cooper Zach Pozen. Icy Astrobiological Environments. Solar System Surfaces. Comets. Interstellar. Interstellar Grains as Reaction Sites. Hydrogen Flow UV-Photolysis Lamp Flux 5 x 10 14 photon cm -2 s -1 Average energy 7.4 eV. - PowerPoint PPT Presentation
Citation preview
Cosmic Ice Laboratory
Marla Moore
Reggie Hudson
Paul Cooper
Zach Pozen
Solar System Surfaces
Comets
Interstellar
Icy Astrobiological Environments
Interstellar Grains as Reaction Sites
Hydrogen Flow UV-Photolysis LampFlux 5 x 1014 photon cm-2 s-1
Average energy 7.4 eV
p+
IR Spectrometer
UV
Focus of Astrobiology Related Research
•Complex organic products from energetically processed nitriles
Infrared SpectroscopyChemical Analysis
•Oxygen/Ozone/Hydrogen Peroxide — Paul Cooper
•Student projectsCH4
C2H4O isomersOCS
Nitrile-CH3CN
•Acetonitrile has been detected on Titan, in cometary comae and in the ISM.
•If bombarded by radiation---
•More complex molecules?
•Prebiotic molecules result—
e.g.Amino acids ?
C
C
N
H
H
H
(Hudson & Moore, Icarus, 2004)
HNC, CH2=C=NH, HCN (?)
OCN−, CH2=C=NH, HCN (?), CO2 (?)
CH3CN
p+
H2O p+
Nitriles Complex OrganicsInfrared Spectroscopy
ketenimine
Formation of Ketenimine and HCN
A structural isomer:
C C N
H
H
H
Energetic input gives rapid isomerization or cleavage of C-C bond?
Formation of OCN-
Polyatomic anion:-O C N
O C N-
Oxidation product of water and CH3CN
Intermediate in oxidation to CO2
Stabilized by resonance
Formation of Carbon Dioxide
•CO2 is an oxidation product of OCN-
?
Room temperature residues
Analysis of residue--Search for amino acid synthesis
.5
.55
.6
.65
.7
3500 3000 2500 2000 1500 1000 500
.5
.55
.6
.65
.7
3500 3000 2500 2000 1500 1000 500
Absorbance / Wavenumber (cm-1) Paged X-Zoom CURSOR
File # 1 : NEWSPCTR11 1/13/2005 1:31 PM Res= 4
288 K Irradiated CH3CN, Next Morning, Under Vacuum
MID IRSpectrum
Nitriles Amino AcidsChemical Analysis
p+
Sample
Aspartic Acid
Glycine
AlanineAlanine
ABAABA
n-propylamine
i- propylamine
Glycine
Work in Progress
• Finish analysis of residues, blanks, and analysis of higher temperature experiments.
•Publish results
•Search for cytosine
and other pyrimidinescyanate (OCN
-)
HC C CN
N
N
NH2
O
H
H
H
energy
H2O
Progress Report 2005
Talks and Posters:InvitedUMDNotre DameRPIIAU-AsilomarPacifiChem
Publications and Proposals:
DPS- posterNAI-Boulder-2 postersAOGS-Singapore-co-organized 2 sesssions-2 talksNASA Laboratory Workshop-2 postersACS-Atlanta-talk, 2 student postersAbSciCon-talk, poster
Hudson and Moore2 published2 in pressco-authored 1 book chapterco authors on A&A benzene related paperHudson only, 1 in press 1 book chapter proposed and accepted (with astrobiology component)1 AGU session proposed and accepted (with astrobiology connection)
Facilities:
•New electron gun has arrived
•Money for new optical bench has been received
http://www.eckerd.edu/academics/chemistry/courses/ch210/
Education outreach:
Astrobiology courses taught
Mentored 3 students
Zach Pozen
2 studentsfrom the US Naval Academy
www-691.gsfc.nasa.gov/cosmic.ice.lab
Web page is up to date
Session 18---Tuesday 3:45
Ice Prebiotic Chemistry of Nitriles: Identification ofComplex Organic Products
Reggie Hudson
Uv and ion bombardmentMeV
Cosmic RayMagnetospheric
H+
On+, Sn+
Bombardment
Photolysis
UV Photons
Sputtering
Radiolysis