UVolution, PROCESS and AMINO: compared photochemistry in low Earth orbit and in the laboratory of prebiotic organic compounds related to small bodies, Titan and Mars H. Cottin1, Y.Y. Guan1, K. Saiagh1, F. Stalport1, E. Arzoumanian1, E.T. Es-Sebbar2, F. Macari1, M. Jérome1, M. Cloix1, Y. Bénilan1, P. Coll1, N. Fray1, M.C. Gazeau1, A. Jolly1, F. Raulin1, C. Szopa3, D. Chaput4, M. Bertrand5, A. Chabin5, F. Westall5, A. Brack5 1LISA,

University Paris Est-Créteil & Paris Diderot, UMR 7583 CNRS, Créteil, France, 2Clean Combustion Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia,3LATMOS, University Paris 6 & Versailles, UMR 8190 CNRS, Verrières le Buisson, France, 4CNES, Centre spatial de Toulouse,18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France, 5CBM, CNRS, Rue Charles-Sadron, 45071 Orléans Cedex 2, France

[email protected]

hv

Δ

40

Irradiance (mW/m²/nm)

lyman α 122 nm 30

Solar flux (near maximum) between 120‐200 nm

20

~1,5.1013 ph.cm‐2.s‐1 10

SOLAR UV

0 100

120

140

160

Wavelength (nm)

180

200

Basics of photochemistry… Modeling photochemistry

J = ∫ σ λ Φλ Iλ dλ λ

A

hν J

Products

absorption cross section (cm²)

photolysis quantum  yield

?

photons flux (photon.cm‐2.s‐1) Solar or lab.

Basics of photochemistry… Modeling photochemistry 5

4

slope : - J

A

hν

Products

ln (A)

3

2

J 1

First order decay

0 0

20

40

60

80

100

time (s)

d [ A] = − J [ A] dt

J = ∫ σ λ Φλ Iλ dλ λ

ln[ A] = ln[ A]0 − J × t t1/2 = ln 2 / J

absorption cross section (cm²)

photolysis quantum  yield

photons flux (photon.cm‐2.s‐1) Solar or lab.

40

Irradiance (mW/m²/nm)

lyman α 122 nm 30

Solar flux (near maximum) between 120‐200 nm

20

~1,5.1013 ph.cm‐2.s‐1 10

SOLAR UV

0 100

120

140

160

180

200

Wavelength (nm)

Lamp flux :  ~5.1014 ph.cm‐2.s‐1

J = ∫ σ λΦλ Iλ dλ λ

UVolution Astrochemistry on Biopan 6 Foton M3 September 14-26, 2007 29 hours of direct exposition to the Sun

Feb., 2008

EXPOSE on the ISS

Space laboratories

UV‐olution :  FOTON‐3M / BIOPAN 6   September 14‐26, 2007

BIOPAN (FOTON)

PROCESS, AMINO : International Space Station •PROCESS – Expose‐E (Columbus) :  Feb. 2008 – August 2009 •AMINO ‐ Expose‐R (Zvezda) : March 2009 – March 2011 (1200 – 2000 hours of exposition)

EXPOSE (ISS)

Space laboratories UVolution Sample Holders ‐> (23 + 37) 60 exposed samples Experimental sets 2x2 flight samples : 2 exposed : vacuum, T, UV 2 not exposed : vacuum, T 2 ground samples : 2 lab control : vacuum, constant T Laboratory photolysis of each molecule (comp. Space vs. Lab. Results)

Space laboratories

EXPOSE

Space laboratories

EXPOSE

Space laboratories 9 mm MgF 2 window Sample deposited on window

9 mm MgF 2 window Sample deposited on window or gaz mixture

recovery of gaseous phase

~9 mm

MgF 2 window

• degradation of solid film • release of gaseous compounds (lost in space ?)

Analyses :  ‐Transmission infrared spectroscopy 

UVolution: RESULTS Absorbance Spectra cell # CO202 (flight exposed): Black : before flight Green : after flight

Spectra cell #CO198 (flight not exposed): Red : before flight Blue : after flight

Glycine (NH2CH2CO2H) Glycine Cell #

exp/not exp Area before (3250‐2470) Area after (3250‐2470)

Variation

CO202

EXPOSED

32,3

28,7

‐11%

CO208

EXPOSED

25,5

22,7

‐11%

CO198

NOT EXPOSED

46,1

47,2

0%

CO199

NOT EXPOSED

28,1

28,2

0%

CO027

GROUND CONT.

28,2

28,3

0%

CO026

GROUND CONT.

31,4

30,8

‐2%

UVolution: RESULTS

Xanthine

Urea

Adenine

Guanine HCN polymer

Molecule J(s-1) / Space glycine 1,0E-06 adenine < 1,9E-7 guanine < 1,9E-7 xanthine 5,0E-07 hypoxanthine < 1,9E-7 urea < 1,9E-7 C3O2 polymer(*) 1,3E-06 polyHCN 8,0E-07 (*) CN band

Rel uncert. 10% 22% 69% 28%

Hypoxanthine Half Life at 1 AU (d) Half Life in ISM* (yr) 2185 8 > 11570 > 41 > 11570 > 41 4553 16 extrapolation > 11570 > 41 > 11570 > 41 1755 6 2834 10

I = 1,04 1013 ph.cm-2.s-1 at 1 A U (Thuillier & al. 2004 ) λ 10+09 > 10+09 2 10+08 3 10+08 *Dark Clouds

Results: laboratory simulations (H2/He lamp) Lamp flux ~ 5 1015 ph.cm-2.s-1

glycine phtolysis with lamp H2/He

Measured by N2O gas actinometry

0,05

y = -8,608E-06x + 4,065E-04 R2 = 9,860E-01

ln (area)

0 -0,05 -0,1 -0,15 -0,2 -0,25 0

5000

10000

15000

20000

25000

30000

time (s)

Molecule

J(s-1) / Lab

Rel uncert.

glycine adenine guanine xanthine hypoxanthine urea C3O2 polymer(*) polyHCN (*) CN band

8,6 10-6 2,7 10-7 < 2,7 10-7 1,3 10-6 3,7 10 -6 < 2,7 10-7 1,3 10-5 2,0 10-6

8% 60% -22% 40% -74% 100%

Half Life measured in the lab. (d) 0,9 30 > 30 6 2 > 30 0,6 4

Results: space exposition Vs. laboratory simulations

J = ∫ σ λ Φ λ Iλ dλ λ

Molecule

glycine adenine guanine xanthine hypoxanthine urea C3O2 polymer(*) polyHCN (*) CN band

J measured in space (s-1)

J' measured in the lab. (s-1)

1,0E-06 < 1,9E-7 < 1,9E-7 5,0E-07 < 1,9E-7 < 1,9E-7 1,3E-06 8,0E-07

8,6 10-6 2,7 10-7 < 2,7 10-7 1,3 10-6 3,7 10-6 < 2,7 10-7 1,3 10-5 2,0 10-6

J' extrapolated at 1 AU (s-1) (lyman α ) 6E-09 8E-10 < 8,2 10-10 4E-09 1,1E-08 < 8,2 10-10 1,1E-08 2E-09

Ratio J' extrapolated (space/lab.) at 1 AU (s-1) (lyman α ) (115-200 nm) 167 < 238 -125 < 17 -118 400

1E-07 1,5E-08 < 8,2 10-10 7E-08 2E-07 < 8,2 10-10 2E-07 3,5E-08

Ratio (space/lab.) (115-200 nm) 10 < 13 -7