Organic material and gases in the early solar system: the meteorite record

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1 rganic material and gases in the early solar system: the meteorite record Laurent Remusat LMCM, Museum National d Histoire Naturelle de Paris remusat@mnhn.fr Laurent Remusat European Conference on Laboratory Astrophysics

2 utline Meteorites are fragments of planets or asteroids falling on Earth. Among them, chondrites provide a record of the solar system initial components delivered to the laboratory. They contain an assemblage of high temperature and low temperature components. The later includes water, organics and noble gases. This talk aims at showing results from geochemical characterization of these components and the related opened questions. Laurent Remusat European Conference on Laboratory Astrophysics

3 Laurent Remusat European Conference on Laboratory Astrophysics

4 Which objects have recorded the solar system formation? Meteorites Cometary grains from Stardust mission Images NASA Micrometeorites Interplanetary Dust Particles : IDPs Laurent Remusat European Conference on Laboratory Astrophysics

Carbonaceous chondrites are undifferenciated meteorites, formed during the early stages of the solar system They contain high temperature components like chondrules and CAIs Murchison 1 cm 300 µm

5 Carbonaceous chondrites are undifferenciated meteorites, formed during the early stages of the solar system They contain high temperature components like chondrules and CAIs Murchison 1 cm 300 µm Allende These components are associated with a matrix containing low temperature constituents like organic matter, clay minerals or noble gases Laurent Remusat European Conference on Laboratory Astrophysics

Carbonaceous chondrites are primitive Their elemental composition fits the solar composition (i.e. almost the bulk solar system) They have trapped the initial constituents of the solar system.

6 Carbonaceous chondrites are primitive Their elemental composition fits the solar composition (i.e. almost the bulk solar system) They have trapped the initial constituents of the solar system. Anders & Grevesse 1989; Lodders 2003 Laurent Remusat European Conference on Laboratory Astrophysics

Parent body processes in carbonaceous chondrites Chondrites parent bodies have accreted

They have then evolved during the 1st millions of years of the solar system.

type: 1 2 3 4 5 6 CI: Ivuna CM: Murchison CR: Renazzo C, CV: Allende New phases are formed,

7 Parent body processes in carbonaceous chondrites Chondrites parent bodies have accreted short live radionucleides and water ice. They have then evolved during the 1st millions of years of the solar system. Hydrothermal alteration High temperature metamorphism Pet. type: CI: Ivuna CM: Murchison CR: Renazzo C, CV: Allende New phases are formed, chemical reactions and isotopic exchange may occur. Parent body processes may alter the signature of solar system processes. Laurent Remusat European Conference on Laboratory Astrophysics

Where is water in chondrites? Paris Mighei Water is trapped in clay minerals, believed to be secondary phases (up to 15 wt%). Water can also be found in nominally anhydrous minerals (like pyroxene).

8 Where is water in chondrites? Paris Mighei Water is trapped in clay minerals, believed to be secondary phases (up to 15 wt%). Water can also be found in nominally anhydrous minerals (like pyroxene). Water origin is usually constrained by and H isotopes. isotopes shows it is solar. H isotopes shows a wide range, reflecting that chondrites have accumulated water from different sources (i.e. formed at different radius in the solar system). Laurent Remusat European Conference on Laboratory Astrophysics

D/H signature and origin of water in chondrites M - Water equilibrium Deloule et al, GCA 1998 Alexander et al, GCA 2010 Extended range of D/H compositions Water M exchange has been suggested but

9 D/H signature and origin of water in chondrites M - Water equilibrium Deloule et al, GCA 1998 Alexander et al, GCA 2010 Extended range of D/H compositions Water M exchange has been suggested but compositions are not consistent with equilibrium. In particular, water is always depleted compared to organic matter. rigin of water in meteorites (and on Earth) is still debated Laurent Remusat European Conference on Laboratory Astrophysics

10 rganic matter in carbonaceous chondrites CC are rich in organic matter (up to 4 wt%). Solvent extraction HF/HCl leaching Soluble organic matter Complex mixing of aliphatic and aromatic hydrocarbons, carboxylic acids, amino acids, etc Insoluble organic matter Main organic component (>75 wt%). complex structure. the less sensitive to terrestrial contamination, quite unreactive. Laurent Remusat European Conference on Laboratory Astrophysics

Where is the organic matter in chondrites?

11 Where is the organic matter in chondrites? Within the matrix Murchison as isolated micron size organic grains and diffuse organic matter. rgueil Si, C et S by NanoSIMS rgueil smium labelling and EDS mapping (Pearson et al., MAPS 2002) 5 µm Fluorescence microscopy (Alpern and Benkheiri, EPSL 1973) Laurent Remusat European Conference on Laboratory Astrophysics

bright. We can distinguish an organic rich particle and a lot of diffuse C (soluble organic matter?

12 How fine is the association organics / matrix minerals? FIB section and TEM Hydrated matrix (clay, sulfates, carbonactes) carbon rganic matter appears in bright. We can distinguish an organic rich particle and a lot of diffuse C (soluble organic matter?) Le Guillou et al., LPSC 2010, 2011, MetSoc 2011, Peeters et al., MetSoc 2011 Laurent Remusat European Conference on Laboratory Astrophysics

13 Structural order of the insoluble organic matter and thermal metamorphism (1) HRTEM of IMs 10 nm High temperature metamorphism Laurent Remusat European Conference on Laboratory Astrophysics

Thermal processing of organic material D band G band

) 2900 C 2000 C 1600 C 1300 C 1000 C 450 C Graphitization

-1 ) Rouzaud et berlin, 1984 Beyssac et al, J. Metam.

14 Thermal processing of organic material D band G band Carbonization Graphitization Raman Intensity (a.u.) 2900 C 2000 C 1600 C 1300 C 1000 C 450 C Graphitization Carbonization Wavenumber (cm -1 ) Rouzaud et berlin, 1984 Beyssac et al, J. Metam. Geology 2002 Laurent Remusat European Conference on Laboratory Astrophysics

15 Structural order of the insoluble organic matter and thermal metamorphism (2) Bands are getting sharper IM from unheated and pristine chondrites Upon heating, the structural order increases, due to reorganization of polyaromatic moeities D band increases Frist steps of carbonization: maturation of organic matter under thermal stress. Quirico et al, MAPS 2003 Bonal et al, GCA 2007 As a consequence, M loses heteroatoms and initial molecular/structural properties. Laurent Remusat European Conference on Laboratory Astrophysics

samples (stardust mission, De Gregorio et

16 Another textural feature: nanoglobules Tagish Lake 140 nm 50 nm Garvie et Buseck, 2004 Garvie et al, 2007 Found in carbonaceous chondrites and cometary samples (stardust mission, De Gregorio et al. GCA 2010). Have been synthesized in lab. (Saito and Kimura ApJ 2009). Laurent Remusat European Conference on Laboratory Astrophysics

17 The molecular structure of the IM Elemental analysis C 100 H N 3,5 S 2 rgueil (CI) C 100 H N 3 S 6,5 Murchison (CM) Laurent Remusat European Conference on Laboratory Astrophysics

chondrite Studying the insoluble organic matter HF/HCl

Average bulk molecular properties IM Pyrolysis and

analytical techniques Molecular level characterization

18 chondrite Studying the insoluble organic matter HF/HCl and solvant extraction Spectroscopy NMR, IR, XANES Average bulk molecular properties IM Pyrolysis and oxidations Permanent comparison between several analytical techniques Molecular level characterization GC-MS / LC -MS Laurent Remusat European Conference on Laboratory Astrophysics

19 Short and branched aliphatic chains CH 3 CH 3 R H CH3 R S R N in pyrroles Derenne et Robert, MaPS, 2010 N H R N CH 3 H R R H R S CH 3 R CH 3 S in thiophenes R R H R R CH3 N Laurent Remusat European Conference on Laboratory Astrophysics S C R N CH 3 H N H CH3 in ether and ester R CH 3 R N R H R S H H R R R R Small and substituted aromatic units

20 To compare with astrophysical molecular models Dartois et al, A&A, 2005 Pendleton and Allamandola, ApJ, 2002 Laurent Remusat European Conference on Laboratory Astrophysics

21 rganic radicals in IM of CI and CM chondrites Radicals are moeities with unpaired electrons, detected by Electron paramagnetic resonance (EPR): IM in rgueil, Murchison and Tagish Lake CH 3 Terrestrial samples CH 2 Binet et al., GCA, 2002 Laurent Remusat European Conference on Laboratory Astrophysics

22 IM also contains diradicaloids Binet et al., GCA, 2004 Diradicaloids are only found in meteorites at the natural state. They represent rather large polyaromatic units (7-10 aromatic rings). Are only found in type 1 and 2 CC). Laurent Remusat European Conference on Laboratory Astrophysics

23 Molecular variations among classes Solid state NMR reveals significant variations in the molecular structure Cody et Alexander, GCA 2005 Laurent Remusat European Conference on Laboratory Astrophysics

24 S-functions in the IM S K edge XANES More oxidized xidation state of S-rich moieties varies depending on the evolution of the parent body. More oxidation with increasing hydrothermal alteration. rthous Daunay et al, EPSL 2010 Laurent Remusat European Conference on Laboratory Astrophysics

25 The insoluble organic matter The IM molecular structure differs from other natural macromolecules but is close to some laboratory synthesized macromolecules. The structure exhibits a high degree of cross linking. Heteroelements chemistry is influenced by parent body processes (except for N): oxidation with hydrothermal alteration (more -rich bonds, oxidized S). Under thermal stress, the structure undergoes reorganization by loss of side chains and heteroelements and aromatization. Laurent Remusat European Conference on Laboratory Astrophysics

26 Soluble organic compounds The largest diveristy for hydrocarbons xidized compounds are the most abundant Several compounds of biological interest Laurent Remusat European Conference on Laboratory Astrophysics

Chirality in meteorites Several classes of compounds can have chiral properties: Amino acids Hydroxy acids Sugars Insoluble organic matter Amino acids have been shown to

27 Chirality in meteorites Several classes of compounds can have chiral properties: Amino acids Hydroxy acids Sugars Insoluble organic matter Amino acids have been shown to express a small enantiomeric excess in meteorites. e.e. also evidenced in the IM (Kawasaki et al. GCA 2006). Laurent Remusat European Conference on Laboratory Astrophysics

28 Enantiomeric excesses in Murchison amino acids: the big debate L-Alanine (ee= 25%): δ 13 C = 27 δ 15 N = 57 D-Alanine: δ 13 C = 30 δ 15 N = 60 L- glutamic acid (ee = 54%): δ 13 C = 6 δ 15 N = 58 D- glutamic acid : δ 13 C = n.d. δ 15 N = 60 Engel et Macko, Nature 1990 et 1997 Terrestrial amino acids: -10 < δ 15 N < 20 et -30 < δ 13 C < -10 Laurent Remusat European Conference on Laboratory Astrophysics

Parent body influence Possible link with the

(Glavin and Dworkin, PNAS 2009) Parent body

Inter- and intra- variations (Pizzarello et

29 Parent body influence Possible link with the hydrothermal alteration on the parent body (Glavin and Dworkin, PNAS 2009) Parent body alteration is known to be heterogeneous Inter- and intra- variations (Pizzarello et al, GCA 2003) Amplification of the e.e. by parent body alteration? Laurent Remusat European Conference on Laboratory Astrophysics

30 Isotopic compositions Tracers of the origin and evolution of organic matter in carbonaceous chondrites Laurent Remusat European Conference on Laboratory Astrophysics

31 Isotopic ratios in chondritic IMs CR IM are 15 N-rich Increasing hydrothermal alteration Increasing thermal metamorphism Alexander et al, GCA, 2010 Laurent Remusat European Conference on Laboratory Astrophysics

Isotopic heterogeneity at the micron scale Isolated organic particles in the matrices of carbonaceous chondrites They exhibit a significant

32 Isotopic heterogeneity at the micron scale Isolated organic particles in the matrices of carbonaceous chondrites They exhibit a significant heterogeneity in D/H, but the textural context is similar Remusat et al., ApJ 2010 Laurent Remusat European Conference on Laboratory Astrophysics

33 Heterogeneities of D distribution in chondritic IM Heterogeneity between chondrites: Parent body processes effects (exchange with water during hydrothermal alteration or loss of components by heating), or chondrites have accreted organics with various isotopic compositions. Heterogeneity within the chondrites Due to selective preservation on the parent body? Accretion of organic particles with various D/H? Laurent Remusat European Conference on Laboratory Astrophysics

, ApJ 2009 In CI, CM and CR chondrites, IMs exhibit D-rich hot spots.

34 These heterogeneities are observed in some IMs NanoSIMS images of the D/H ratio of IMs MI Murchison MI Kainsaz (C3) Remusat et al., ApJ 2009 In CI, CM and CR chondrites, IMs exhibit D-rich hot spots. Those hot spots are not found in other classes. Interestingly, their occurrence match with the presence of organic radicals. Laurent Remusat European Conference on Laboratory Astrophysics

35 What are those D-rich hot spots? 2 possible interpretations for the occurrences of D-rich hot spots: They are preserved interstellar organic grains (Busemann et al. 2006) They are the fingerprint of the occurrence of unusual molecular moieties, with unusual isotopic fractionations (Remusat et al. 2009). rganic radicals may be responsible for the occurrence of D-rich hotspots: radicals exhibit a very high D enrichment (D/H= Gourrier et al. 2008), they are heterogeneously distributed in the IM and they are thermally labile. Laurent Remusat European Conference on Laboratory Astrophysics

36 D distribution at the molecular scale in rgueil IM Remusat et al., ApJ 2009 Laurent Remusat European Conference on Laboratory Astrophysics

37 Interpretation of isotopic compositions Is it an interstellar signature? Not necessarily: No isotopic anomalies in 13 C (but we have found presolar grains with large deviations from solar ratio). Muñoz-Caro et al. A&A 2006: UV and ion irradiation in the diffuse insterstellar medium would erase any signature in D and 15 N. A local origin for the isotopic signature has to be considered In any case, large fractionations in D (and in 15 N) are likely the result of low temperature chemistry. Likely involve ion/molecule reactions (shown to fractionate H isotopes in organic molecules). However, what about the parent body processes effects? Laurent Remusat European Conference on Laboratory Astrophysics

$Calculation: H isotope fractionation in water - rganic matter system$ , ApJ 2010 In any case, at the equilibrium, the organic H is depleted

38 Calculation: H isotope fractionation in water - rganic matter system Ab initio calculations Ethyl benzene Remusat et al., ApJ 2010 In any case, at the equilibrium, the organic H is depleted in D compared to water. Laurent Remusat European Conference on Laboratory Astrophysics

39 Is there any isotopic exchange between organics and the hydrated matrix? H/Si and C/Si profiles through organic rich grains in the matrix of rgueil consistent with organic matter embedded in inorganic matrix D/H and C/H profiles are similar: D does not significantly diffuse from the D-rich organic matter to the D-depleted matrix (required in the case of isotopic exchange). The H isotopic exchange does not appear significant enough to alter the D rich signature of organic matter in chondrites Remusat et al., ApJ 2010 Laurent Remusat European Conference on Laboratory Astrophysics

40 A model for the origin of IM grains in carbonaceous chondrites Infall of interstellar M? Laurent Remusat European Conference on Laboratory Astrophysics

41 Noble gases in chondrites And the link with organic matter Laurent Remusat European Conference on Laboratory Astrophysics

42 Noble gases in chondrites Noble gases do not make covalent bonds. Several components can be distinguished: the main are solar (implanted) and planetary (accreted). We can also isolate in situ noble gases produced by nuclear reactions (spallation or radioactive decay) Reservoirs are identified by elemental and isotopic compositions: Q phase (IM?) normal P3 : nanodiamonds normal U: Ureilite (graphite ou diam.) HL : presolar diamonds G: presolar graphites N : presolar graphites or SiC Wieler et al, 2006, MESS II. Laurent Remusat European Conference on Laboratory Astrophysics

43 Q phase Noble gases pattern of HF/HCl residues Striking similarity of the patterns of different chondrites Abundance higher in less heated and less altered chondrites Busemann et al., MaPS 2000 Laurent Remusat European Conference on Laboratory Astrophysics

44 Is the IM the Q phase? The Q-phase is contained in the acid residue. All the gases are released at the same temperature. It has been shown that modifying the structure of the IM releases noble gases with Q phase composition (Marrocchi et al. 2005): Huss et al., GCA, 1996 Laurent Remusat European Conference on Laboratory Astrophysics

45 However The origin of the noble gases content in chondrites is still a matter of debate. Several groups have attempted to reproduce the pyridine experiment, but did not get the same result (Spring et al. 2010, Matsuda et al. 2010) How are they fractionnated? How are they trapped? Laurent Remusat European Conference on Laboratory Astrophysics

46 Conclusions How organics, water and noble gases accreted on carbonaceous chondrites? Laurent Remusat European Conference on Laboratory Astrophysics

47 Water accreted as ice grains or hydrated minerals. Noble gases are likely trapped on grains, accreted on the parent body. Some are implanted or produced by spallation. rganic matter is accreted as organic rich grains possibly associated with ice. Soluble compounds are released by ice melting and redistributed in the parent body. Secondary reactions likely occur on the parent body, inducing the formation of new compounds and modification of pre existing ones. Laurent Remusat European Conference on Laboratory Astrophysics

A possible scenario for accretion and parent body evolution

redistribution in cracks Murchison rgueil M redistribution

of the M Hydrous phases nucleation next to M grains Laurent

48 A possible scenario for accretion and parent body evolution Accretion / Dust coalescence Water ice melting rganic matter redistribution in cracks Murchison rgueil M redistribution and mixing into forming phyllosilicates + Aqueous chemistry of the M Hydrous phases nucleation next to M grains Laurent Remusat European Conference on Laboratory Astrophysics

49 Thank you! And many thanks to: JN Rouzaud (ENS Paris) C. Le Guillou (Univ New Mexico) J Eiler, Y Guan (Caltech) S Derenne (UPMC, Paris) S Bernard, B Zanda, F Robert (MNHN Paris) FR rthous-daunay (WashU) Laurent Remusat European Conference on Laboratory Astrophysics

Comet Science Goals II

Comet Science Goals II {questions for goals} Don Brownlee Did the events postulated by the Nice Hypothesis really happen? Were there wide-spread solar system wide impact events that were coeval with the