Enceladus

1. Enceladus Sara Faggy Cédric Humbert Catherina Jansen Silvia Moriano Pachigar Saumeel

2. What is Enceladus? Athena and Enceladus. Musée du Louvre, Paris, France

3. What is Enceladus?

4. The Astrophysical Aspects

5. When did we first encounter Enceladus?

6. Cassini Mission

7. Cassini Mission

9. Astrophysical characteristics Dimension: Mass: Mean Density: Equatorial surface gravity: Escape velocity: Rotation period: Axil tilt: Apparent Magnitude: Surface temperature (mean) : 252.1 ± 0.1 km =(0.0395 Earths) (1.080 22 ± 0.001 01) × 1020 kg =(1.8×10-5 Earths) 1.609 6 ± 0.002 4 g/cm3 0.111 m/s^2 (0.011 3 g) 0.239 km/s (860.4 km/h) Synchronous Zero 11.7 75K

10. Orbital parmeters Major Axis Orbilat period Inclination (to Saturn's equator) Eccentricity 238 020 Km 32 h 53 min 07s 0,02° 0,0045

11. The Biological Aspects

12. Production of organic compounds by interstellar cloud CO CO2 NH3 CH2OH H2O CH4 C2 and N2 and others organic compounds

13. Production of organic compounds by interstellar cloud Cosmic radiations (UV, gamma rays...))‏ CO CO2 NH3 CH2OH H2O CH4

14. Production of organic compounds by interstellar cloud Cyanic acid Formaldehyde Alanine Acetonitrile Acetaldehyde Formamide Ethylamine And other organic compounds.....

15. Enceladus Meteorits and comets as carriers

16. Enceladus Cosmic radiations Degration/other chemical reactions enanthioselective photolysis occurs during the voyage

17. Degradation / other chemical reactions/ enanthioselective photolysis/ and protection Production of L-amino acids, D-sugars, nucleobase like compounds and other precursors of biomolecules L-amino acid (left) and D-amino acid (right)‏ Purine likecompounds

18. Impact with the satelite and delivery of survival organic compounds on the crust

19. Production of organic compounds by volcanism

20. Production of organic compounds by volcanism Volcanism Heating of sea salts Catalysis of of follow reaction Production of HCL and mineral ions + Dipyrrin redox active metal ion chelator Pyrrole Formaldehyde

21. Production of organic compounds by hydrothermal vents

22. Production of mineral ions Production of simple molecules like CO2/H2/NO2...., which form organic compounds

23. During the freezing of water, solutes are excluded and chemical reactions occur between the solutes and produce some organic compounds

25. Production of biomolecules by clays Adsorption of organic compound by montmorillonite Structure of montmorillonite

26. Production of organic compounds by interstellar cloud Montmorillonite are able to capture, retain, and protect charged compounds and minerals due to their charged structure. This capacity of adsorption is due to a high cationic interchange capacity and an high area of adsorption. These specificities of montmorillonite permit it to concentrate biomolecules. Montmorillonite presents an enantioselective uptake/protection of compounds, for example montmorillonite retain preferencially L form of amino acids This phenomenon permits some reactions such as the phosphorylation of AMP, amino acids polymerisation of active nucleotides in RNA less than 50 mers (with a preferencial bond formation between 2'-5' or 3'-5' positions)‏or formation of polypeptidic chain sometimes by recruiting some mineral ions for catalysis.The mechanism for this is temperature, pressure, and pH dependant. Enceladus has the adequate conditions to permit such reactions.

27. What are Extremophiles? ‘Organisms that thrive in extreme environments; if in more than one extreme then called polyextremophiles’ Rothschild and Mancinelli

28. What are Extremes? ‘Everything in Moderation’ Aristotle

29. Extremophiles in the case of Enceladus

30. Extremophiles in the case of Enceladus Surface • - Minimal Atmosphere • Very low Temperatures • Dessication • - No oxygen Geysers • Varying temperature • Pressure • - pH (Not confirmed) Water Reservoir - Has ideal conditions for life

31. Ecosystems on Enceladus • We can describe two possible ecosystems that may exist on Enceladus. Methanogen-based community Sulfur reducing-based community Primary producers are methanogens that consume H2. Ecosystems within a tidally heated liquid water reservoir on Enceladus. Primary producers are sulfurreducing bacteria. 4H2: from disotiation of H2O by radioactive decay. SO42-: reaction o oxidants with FeS2. 4H2 + CO2 → CH4 + 2H2O 4H2+ H+ + SO42- → H2S+ 2H2O+ 2OH-

32. Ecosystems on Enceladus • We can describe two possible ecosystems that may exist on Enceladus. Methanogen-based community Ice cover Primary producers are methanogens that consume H2. Ecosystems within a tidally heated liquid water reservoir on Enceladus. Ocean Biology: H2+CO2→CH4+H2O H2 CH4 Rock CH4+H2O → H2+CO2 4H2 + CO2 → CH4 + 2H2O

33. Ecosystems on Enceladus • We can describe two possible ecosystems that may exist on Enceladus. Methanogen-based community Sulfur reducing-based community Primary producers are methanogens that consume H2. Ecosystems within a tidally heated liquid water reservoir on Enceladus. Primary producers are sulfurreducing bacteria. 4H2: from dissotiation of H2O by radioactive decay. SO42-: reaction o oxidants with FeS2. 4H2 + CO2 → CH4 + 2H2O 4H2+ H+ + SO42- → H2S+ 2H2O+ 2OH-

34. Origin of life on Enceladus • Speculations about life on Enceladus are necessarily based on our understanding of life on Earth. Defining the growth requirements for life - Liquid water - Energy source - Carbon - Other elements such as N, P, S. Enceladus has all of these

35. Origin of life on Enceladus Three main categories origin of life on Earth Extraterrestial origin of life Panspermia Organic origin of life Terrestial origin of life Chemosynthetic origin of life

36. Origin of life on Enceladus Panspermia - Extraterrestrial origin of life. -Enceladus would share the same origin and, therefore, the same biochemistry as life on earth. Organic origin of life - Applied to Enceladus: the organic soup model might involve the formation of Enceladus from organic-rich ices similar to cometary materials. Chemosynthetic origin of life - In this scenario, life begins at the interface where chemically rich fluids heated by tidal dissipation emerge from below the sea floor.

37. The Technological Aspects

38. Cassini Instruments: -Cassini Plasma Spectometer (CAPS) -Cosmic Dust Analyser (CDA) -Composit Infrared Spectrometer (CIRS) -Ion and Neutral Mass Spectrometer (INMS) -Imaging Science Subsystem (ISS) -Dual techinque Magnetometer (MAG) -Magnetospheric Imaging Instrument (MIMI) -Cassini Radar (RADAR) -Radio and Plasma Wave Spectometer (RPWS) -Radio Science Subsystem (RSS) -Ultraviolet Imaging Spectrograph (UVIS) -Visible and Infrared Mapping Spectometer (VIMS)

39. Ultra Violet Imaging Spectrograph

40. Ion and Neutral Mass Spectrometer

41. Visible and Infrared Mapping Spectrometer

42. Composite Infrared Spectrometer

43. ImagingScience Subsystem

44. The Future

45. Our Proposal Enceladus at prensent is not completely understood, though the little data collected from Cassini-Huygens shows promise for life. Not being the current focus of the european and american space agencies, due to commitments with studying Mars. If a mission to enceladus ever arises we propose that the following are tested: Test Water ReservoirCheck Plumes -Bacterial By Products -ATP -Simple Sugars Check for Sulphur

46. Thank you for your attention

47. References Parkinson, C.D., Liang, M.C., Hartman, H., Hansen, C.J., Tinetti, G., Meadows, V. Kirschvink, J.L. , Yung, Y.L. 2007. Enceladus: Cassini observations and implications for the search for life. Astronomy&Astrophysics , 463: 353-357. Porco, C. 2009. L’inquieto mondo di Encelado. Le scienze, 487: 42-51. Postberg , F.,. Kempf , S., Schmidt, J., Brilliantov, J., Beinsen A. Abel , B., Buck, U., Srama, R. 2009. Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus. Nature, 459: 1098-1101. Spencer, J.R., Pearl, J.C., Segura, M., Flasar, F.M., Mamoutkine, A., Romani, P., Buratti, B.J., Hendrix, A.R., Spilker, L.J., Lopes, R.M.C. 2006. Cassini Encounters Eceladus: Backgraund and the Discovery of south polar hot spot. Science, 311: 1401-1405.