Talk Astrobiologia Ifusp2007

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    ASTROBIOLOGIAA vida no contexto

    csmico

    C. A. Wuensche

    III Semana da Fsica - UFSCar07 de agosto de 2007

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    Resumo

    Introduo

    Principais reas de discussoHabitabilidade planetria

    ExoplanetasExtremfilos e origem da vida

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    A Biophilic Universe

    Martin Rees

    Our Cosmic Habitat

    A universe hospitable to life what we may call

    a biophilic universe has to be very special in

    many ways. The prerequisites for any life (long-lived stars, a periodic table of elements with

    complex chemistry, and so on) are sensitive to

    physical laws and could not have emerged from a

    Big Bang with a recipe that was even slightly

    different.

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    A cosmological perspective tosearch of life in the Universe...

    Spergel et al., WMAP series, 2006

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    Other nonluminouscomponentsIntergalactic gas: 3.6%

    Neutrinos: 0.1%Supermassive BHs: 0.04%

    Luminous matterStars and luminous gas: 0.4%

    Radiation: 0.005%

    A cosmological perspective tosearch of life in the Universe...

    Spergel et al., WMAP series, 2006

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    Other nonluminouscomponentsIntergalactic gas: 3.6%

    Neutrinos: 0.1%Supermassive BHs: 0.04%

    Luminous matterStars and luminous gas: 0.4%

    Radiation: 0.005%

    A cosmological perspective tosearch of life in the Universe...

    Life building blocks come

    from these components...

    Spergel et al., WMAP series, 2006

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    Other nonluminouscomponentsIntergalactic gas: 3.6%

    Neutrinos: 0.1%Supermassive BHs: 0.04%

    Luminous matterStars and luminous gas: 0.4%

    Radiation: 0.005%

    A cosmological perspective tosearch of life in the Universe...

    Life building blocks come

    from these components...

    b= 0.04 T

    Spergel et al., WMAP series, 2006

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    Other nonluminouscomponentsIntergalactic gas: 3.6%

    Neutrinos: 0.1%Supermassive BHs: 0.04%

    Luminous matterStars and luminous gas: 0.4%

    Radiation: 0.005%

    A cosmological perspective tosearch of life in the Universe...

    Life building blocks come

    from these components...

    b= 0.04 T

    Spergel et al., WMAP series, 2006

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    Other nonluminouscomponentsIntergalactic gas: 3.6%

    Neutrinos: 0.1%Supermassive BHs: 0.04%

    Luminous matterStars and luminous gas: 0.4%

    Radiation: 0.005%

    A cosmological perspective tosearch of life in the Universe...

    Life building blocks come

    from these components...

    b= 0.04 T

    LETS GIVE IT UP!

    Spergel et al., WMAP series, 2006

    NOT!5

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    Fundamental questions for

    astrobiology How does life begin and evolve?

    Does life exist elsewhere in the Universe?

    What is the future of life on Earth and beyond?

    From The Astrophysical Context of Life (http://www.nap.edu/catalog/

    11316.html)

    Astronomy provides the fundamental underpinnings for life: space

    and time.

    The Universe is filled with billions of galaxies, where there may

    be possible sites for the origin and evolution of life.

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    How can we define life?

    Complex and diversified interactions with the environment

    System out of thermodynamical equilibrium

    Memory + reading/recovering mechanism

    High information content and self-replication capability

    Restrictive hipothesis... Complex systems? Liquid crystals, plasmas... Chemical system? C, Si?

    Liquid millieu? Why H2O?

    Existence of a solid/liquid interface?

    J. Schneider, astro-ph/9604131, Szostak et al., Nature, 2001, Bains, Astrobiology 2005,

    Lunine (2005)

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    How can we define life?

    Complex and diversified interactions with the environment

    System out of thermodynamical equilibrium

    Memory + reading/recovering mechanism

    High information content and self-replication capability

    Restrictive hipothesis...

    Complex systems? Liquid crystals, plasmas... Chemical system? C, Si?

    Liquid millieu? Why H2O?

    Existence of a solid/liquid interface?

    J. Schneider, astro-ph/9604131, Szostak et al., Nature, 2001, Bains, Astrobiology 2005,

    Lunine (2005)

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    How can we define life?

    Complex and diversified interactions with the environment

    System out of thermodynamical equilibrium

    Memory + reading/recovering mechanism

    High information content and self-replication capability

    Restrictive hipothesis...

    Complex systems? Liquid crystals, plasmas... Chemical system? C, Si?

    Liquid millieu? Why H2O?

    Existence of a solid/liquid interface?

    J. Schneider, astro-ph/9604131, Szostak et al., Nature, 2001, Bains, Astrobiology 2005,

    Lunine (2005)

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    Galactic and Planetary

    Habitability

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    Cosmological and galactic issues

    What sorts of environments are needed?

    What is the adequate time span? Once formed,

    planets evolve smoothly, but the same does nothold for our known life forms.

    Initial Universe conditions, galactic and stellarevolution have spread out the building blocksfor life as we know it.

    How biofriendly should a galaxy be, in order tofoster origin and evolution of life?

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    Galaxy Formation Habitability

    Galaxies are natural cells from which the Universe iscomposed.

    Stars live in galaxies, and are responsible for the galacticchemical evolution.

    Necessary levels of chemical abundances and radiation fieldsneeded for the rise of life

    Early galactic evolution

    starburstsdust and molecules complex chemistry.

    CNO synthesized by stars in early galaxies allow for the

    building blocks of organic chemistry to be present since theUniverse was ~ 200 million years.

    Development of complexity life

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    Lineweaver et al., Science, 303, 59 (2004)

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    HABITABLE ZONE (68% e 95%)

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    Probabilities for the GHZ

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    b b l f h G

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    Probability of star formation rate (SFR)

    Typically 1 Solar Mass/year

    Probabilities for the GHZ

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    P b bili i f h GHZ

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    Probability of star formation rate (SFR)

    Typically 1 Solar Mass/year

    Probability of Forming Rock Planets (Pmetals)

    Highly sensitive to the metallicity

    Probability of destroying, producing and harboring Earths

    Probabilities for the GHZ

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    P b biliti f th GHZ

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    Probability of star formation rate (SFR)

    Typically 1 Solar Mass/year

    Probability of Forming Rock Planets (Pmetals)

    Highly sensitive to the metallicity

    Probability of destroying, producing and harboring Earths

    Probability of Evolution over Biological Timescales (Pevol)

    Darwins theory requires long timescales

    Pevoldepends on tevo (tevol = 4 Gyr for Earth)

    tevol could be shorter than 4 Gyr?

    Probabilities for the GHZ

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    P b biliti f th GHZ

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    Probability of star formation rate (SFR)

    Typically 1 Solar Mass/year

    Probability of Forming Rock Planets (Pmetals)

    Highly sensitive to the metallicity

    Probability of destroying, producing and harboring Earths

    Probability of Evolution over Biological Timescales (Pevol)

    Darwins theory requires long timescales

    Pevoldepends on tevo (tevol = 4 Gyr for Earth)

    tevol could be shorter than 4 Gyr?

    Probability of Survival to Galactic Violent Events (PSN - Horvath e Galante,

    Astrobiology 2006)

    Pevoldepends on past events through tSN

    For Earth, tSN = tevol = 4 Gyr (maybe shorter!)

    Other killers: GRBs, GMClouds, AGNs

    Probabilities for the GHZ

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    Friaa et al., ApJ 2006 (submitted)

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    R t d t ti f PANH i th IR

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    H

    C

    N

    Recent detection of a PANH in the IRHudgins et al. ApJ, 2005

    Spitzer detected PANHs in various galaxies, besides our own. First direct evidence for the presence of a prebiotic interesting compound in

    space. Presence of N is essential in biologically interesting compounds (chlorophyll). The presence of a planet is no longer necessary for the formation of a PANH.

    Component of caffeine

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    Stellar habitable zone

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    Stellar habitable zone

    R

    Main assumptions: Surface H2O for ~ Gyear, geological activity, CO2-H2O-N2

    atmosphere, B-field, climate stability, resistance to catastrophes for ~ Gyear

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    Stellar habitable zone

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    Stellar habitable zone

    R

    Main assumptions: Surface H2O for ~ Gyear, geological activity, CO2-H2O-N2

    atmosphere, B-field, climate stability, resistance to catastrophes for ~ Gyear

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    IRS-46 spectrumhttp://www.nasa.gov/lb/vision/universe/starsgalaxies/spitzer-20051220.html

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    IRS-46 spectrumhttp://www.nasa.gov/lb/vision/universe/starsgalaxies/spitzer-20051220.html

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    IRS-46 spectrumhttp://www.nasa.gov/lb/vision/universe/starsgalaxies/spitzer-20051220.html

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    Formation and evolution of life

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    ~ 90% of all Earths biomass!

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    Catling

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    O i f E th h bit bilit

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    Our recipe for Earth s habitability

    1)Liquid water allowed microbes to originate and evolve

    2)Plate tectonics replenished CO2

    for life to persist

    3)A magnetic field protected atmospheric gases fromescape (except H, He)

    Microbes made O2, CH4 CH4 then O2 dominated

    Ozone layer formed at ~ 2.3 Gy

    Simple algae, fungi developed

    More O2 and animals at 0.6 Gy Modern humans at 2 My

    This seminar...

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    Exoplanets

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    203 planetas175 sist. planetrios

    20 sistemas mltiplos

    4 planetas

    4 planetas

    4 planetas

    ltimo acesso: 27/07/2007

    Fonte: http://www.obspm.fr/encycl/catalog.htmlCapacidade existenteProjetada (10 20 a)

    Deteces primrias

    Acompanhamentos

    N-sistemas? - Incertezas

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    All Catalogs (update : 27 July 2007)

    http://www.obspm.fr/encycl/catalog.htmlhttp://www.obspm.fr/encycl/catalog.htmlhttp://exoplanet.eu/catalog-all.php
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    All Candidates detected248 planets

    Candidates detected by radial velocity 202 planetary systems

    (update: 09/07/2007) 236 planets

    25 multiple planet systems

    Candidates detected by transit 23 planetary systems

    (update: 09/07/2007) 23 planets

    0 multiple planet systems

    Candidates detected by microlensing 4 planets

    update : 10/06/2006

    Candidates detected by imaging 4 planets

    update : 24 /07/2006

    Candidates pulsar planets 2 planetary systems

    update : 15/10/2006 4 planets1 multiple planet system

    - Unconfirmed, controversial or retracted planets: 2

    update : 06 July 2007

    - Candidate "cluster" and "free-floating" planets: 3

    update : 31 August 2006

    http://exoplanet.eu/catalog.php

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    Main techniques

    http://exoplanet.eu/cat-freefl.htmlhttp://exoplanet.eu/catalog-pulsar.phphttp://exoplanet.eu/catalog-imaging.phphttp://exoplanet.eu/catalog-imaging.phphttp://exoplanet.eu/catalog-microlensing.phphttp://exoplanet.eu/catalog-microlensing.phphttp://exoplanet.eu/catalog-transit.phphttp://exoplanet.eu/cat-freefl.htmlhttp://exoplanet.eu/cat-freefl.htmlhttp://exoplanet.eu/catalog-contro.phphttp://exoplanet.eu/catalog-contro.phphttp://exoplanet.eu/catalog-pulsar.phphttp://exoplanet.eu/catalog-pulsar.phphttp://exoplanet.eu/catalog-imaging.phphttp://exoplanet.eu/catalog-imaging.phphttp://exoplanet.eu/catalog-microlensing.phphttp://exoplanet.eu/catalog-microlensing.phphttp://exoplanet.eu/catalog-transit.phphttp://exoplanet.eu/catalog-transit.phphttp://exoplanet.eu/catalog-RV.phphttp://exoplanet.eu/catalog-RV.phphttp://exoplanet.eu/catalog-all.phphttp://exoplanet.eu/catalog-all.php
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    Main techniques

    Radial velocity (187 planets) Both planets spin around the center of mass of the system.

    The larger the planet mass or the smallest the distance between starand planet, the larger the star movement.

    Transit (9 planets) Orbits practically perpendicular to the plane of the sky (i=90o). The planet mass is determined by radial velocity; the transit tells us

    about the radius.

    Telescopes on the ground are able to detect only large planets; for

    Earth-like planets, satellite observations are required.

    Microlensing (4 planets) Gravity due to an object between the source and us bends the ligth of

    the source

    Massive objects in the Galactic halo may act as gravitational lens.25

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    Radial Velocity

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    Gravitational

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    Transit of extrasolar planets

    http://www.iac.es/galeria/hdeeg/OSNanimlastmont.gif
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    p

    http://www.iac.es/galeria/hdeeg/OSNanimlastmont.gif

    ~0,02

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    Kepler

    http://www.iac.es/galeria/hdeeg/OSNanimlastmont.gifhttp://www.iac.es/galeria/hdeeg/OSNanimlastmont.gifhttp://www.iac.es/galeria/hdeeg/OSNanimlastmont.gif
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    Darwin

    TPF (Terrestrial Planet Finder)

    COROTcom 30% de participao

    brasileira (INPE tambm)!

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    Possibility of remote detection of lifeExplore the contrast star/planet in thermal IR (Des Marais et al 2002 Segura et al 2003)

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    Explore the contrast star/planet in thermal IR(Des Marais et al. 2002, Segura et al. 2003)

    > 106

    Porto de Melo et al., Astrobiology, 2006

    CO2

    15 m

    O3

    9.6 m

    CH4

    7.7 m

    H2O

    6.3 m +

    12 m band

    Window at 8-12 m: Tsurface

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    A. Chian presented a technique to detect exoplanets via radio emission.Coronal Mass Ejections (CME) from a stellar active region may cause

    geomagnetic storms, which can be seen at large distances. Chian

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    Extremophiles and the

    origin of life

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    Temperature limits for lifea

    ry2001)

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    The highest and lowest temperature for each major taxon is given. Archaea are in red, bacteria in blue,

    algae in light green, fungi in brown, protozoa in yellow, plants in dark green and animals in purple.Lifeinextremeenvironme

    nts,

    LJRothschild&RLMancinelli,Nature409,

    1092-

    1101(22Februa

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    Extremophiles who are they?

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    t e op es w o a e t ey?

    We have more microbe cell than us-cells in our body.

    The first life form on Earth, and the only one for the

    first 3 billion years, was a microbe.

    Microbes can live in REALLY extreme conditions.

    There is more life within the Earth (a few feet below)

    than on the Earths surface.

    Most probable candidates to an E.T. life form.

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    Extremophiles who are they?

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    p y

    We have more microbe cell than us-cells in our body.

    The first life form on Earth, and the only one for the

    first 3 billion years, was a microbe. Microbes can live in REALLY extreme conditions.

    There is more life within the Earth (a few feet below)

    than on the Earths surface.

    Most probable candidates to an E.T. life form.

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    Extremophilessurvival chart

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    Temperature: -15 C < T < 230 C 0.06 < pH < 12.8

    0 < Pressure < 1200 atm

    No mandatory oxygen-based metabolism

    20-40 Myears of dormancy

    2

    years in space, at 20 K, with nonutrients, water and exposed to radiation

    (Strep. Mitis)

    survival chart

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    http://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htmhttp://willmclaughlin.astrodigitals.com/Antarctica/Dry_360.htm
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    Adapted from F. Souza-Barros, 2006

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    Adapted from F. Souza-Barros, 2006

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    What is being done in Brazil?

    Astronomy

    Biology

    Chemistry

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    Survival of aminoacids and nucleobases in ISM andIPM (Pilling et al., 2006)

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    20 Amino acids

    Glycine Alanine Valine

    Leucine

    Serin Glutamine

    Lysine

    Asparagine

    Arginine

    Glutamicacid

    Asparticacid

    Isoleucine

    Threonine

    IPM (Pilling et al., 2006)

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    Our heroes

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    20 Amino acids(cont)

    CysteineMethionine

    Proline

    TryptophanePhenylalanine

    Histidine

    Tyrosine

    Hidroxylamine

    Detected precursor molecules!

    Acetic acid

    Formic acid

    Methanolamine

    NH2CH2

    NH2CH

    NH

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    Our heroes

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    5 Nucleobases

    Adenine GuanineCytosine ThymineUracil

    Pyrimidines Purines

    PyrimidinePyridine

    Detected precursor molecules!

    Hydrogen

    Cyanide

    Acetylene Purine

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    How they are born?

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    X-ray

    UV

    UV

    HCOOH

    HCOOH

    X-ray

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    How they are found?

    IR Telescopes ( b l l )

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    Radiotelescopes (rotational lines)

    IR-Telescopes (vibrational lines)

    Itapetinga, SP

    VLA

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    How they are found?

    IR Telescopes ( ib i l li )

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    Radiotelescopes (rotational lines)

    IR-Telescopes (vibrational lines)

    Itapetinga, SP

    VLA

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    Gaseous Pillars Eagle Nebula Key hole Nebula

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    Hale-Bopp MurchinsonTitan

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    Photoionization using synchrotron light

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    TGM e SGM bean line (VUV & soft X-ray)

    12-22eV

    C1s (290eV)

    N1s (410eV)

    O1s (540ev)

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    The technique

    i f li h S O S

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    Time-of-Flight Mass Spectometry; TOF-MS

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    Where arethe nucleobases?

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    Where are the nucleobases?

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    Why we don't observe them?

    Main reasons for no detection. Life time to short to sustain the column density above

    the detection limit. Low resistance to radiation field.

    Low efficient pathway formation. Low density Large partition function. Many ro-vibrational lines with

    low intensity.

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    Where are the nucleobases?

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    Why we don't observe them?

    Main reasons for no detection. Life time to short to sustain the column density above

    the detection limit. Low resistance to radiation field.

    Low efficient pathway formation. Low density Large partition function. Many ro-vibrational lines with

    low intensity.

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    Where are the nucleobases?

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    Why we don't observe them?

    Main reasons for no detection. Life time to short to sustain the column density above

    the detection limit. Low resistance to radiation field.

    Low efficient pathway formation. Low density Large partition function. Many ro-vibrational lines with

    low intensity.

    If we'll go there, and look for them using amicroscope or other device?

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    Biomolecules results

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    Amino acids

    survival: ~ 1% (16 eV); 0% (> 20 eV )

    main photoproducts (Fingertips): COOH, HCNH, ...

    Nucleobases

    survival: ~ 30% (16 eV); ~ 20% (20eV ); ~ 0.5% (> 100eV)

    main photoproducts: HNCO, HCN, NCO, ...

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    Biomolecules results

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    Amino acids

    survival: ~ 1% (16 eV); 0% (> 20 eV )

    main photoproducts (Fingertips): COOH, HCNH, ...

    Nucleobases

    survival: ~ 30% (16 eV); ~ 20% (20eV ); ~ 0.5% (> 100eV)

    main photoproducts: HNCO, HCN, NCO, ...

    Lets try to look for these guys using their parts(pieces)?

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    SEARCHING PERSPECTIVES

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    Follow-up of growth & metabolism ofextremophiles under simulated planetary/satellite conditions

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    Tit

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    Lago de Hidrocarbonetos?

    Rios de Metano?

    Niemam et al. 2005, Nature, 438, 779.

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    ASTROBIOLOGICALLY INTERESTINGSTARS NEAR THE SUN

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    Porto de Mello et al., Astrobiology, 6, 308-331 (2006)

    Goal: to establish state of the art criteria for selectingstars which might be hosts to remotely detectable

    biospheres

    Criteria: Liquid water, geologic activity, long term

    climate stability

    stellar mass, stellar chemical

    composition, stellar age

    Adequate Time Scales:

    bioproductivity timescale, oxygenationtime scale, stellar age

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    Continuously Habitable Zone and Timescales

    The Habitable Zone ConceptANALYSIS

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    Continuously Habitable Zone and Timescales

    The Habitable Zone ConceptANALYSIS

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    Upper mass limitM ~ 1.2 solar

    masses

    Lower mass limit

    M ~ 0.7 solarmasses

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    The Bioproductivity Issue

    The Habitable Zone ConceptANALYSIS

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    Age of highlydiversified

    biosphere

    is less than 20%

    of total biospherelifetime

    Too advancedan ageis a liability

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    The 13 biostars within 33 light-years

    HD Name mass age [Fe/H] orbit rank

    NOT ONE OF THEM WITH PLANETS !RESULTS

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    g [ ]

    1581 Tuc ~ ~ ~ > 4628 < ? < ~

    10476 107 Psc < ? < >

    16160 < ? ~ >

    32147 < ~ > >

    100623 < > < >

    102365 < > < >

    109358 CVn > ~ < ~

    115617 61 Vir ~ ~ ~ >

    185144 Dra < > < >190248 Pav > ~ > ~

    192310 < > ~ >

    219134 < ? ~ >

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    Present results

    WE CAN quantitatively rank nearby stars as astrobiological

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    q y y g

    targets : completeness of available data is essential;

    7% of neighborhood stars are interesting;

    2% only if we take galactic orbits as relevant;1% only is actually similar to the Sun;

    Observational and theoretical work should continue on:

    Completeness of stellar database of nearby objects;Habitability ofmultiple stars;

    Stabilityof biospheres againstgalactic catastrophes;

    Habitability criteria for planets different from the Earth;

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    Any alternatives at this point?

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    Other liquids may define other biochemistries Ammonia (Jupiter satellites), methane/ethane

    (Titan), nitrogen (silicon-oriented)

    Light (mostly IR) on the surface of Titan may allow

    photosynthesis-like processes, even at lowtemperatures.

    Chemolitotrophy possibly available in any liquid

    environment (Galilean satellites).

    Maybe a new definition of Galactic and Stellar

    Habitable Zones? (Wuensche, Lage, et al.,Astrobiology 2006, submitted)

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    OUR SOLAR SYSTEMS

    LIQUID POSSIBILITIES

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    Water-based oceans

    Other liquid possibilities

    water/am

    monia

    (surf

    acelake

    s)

    water/am

    monia

    (sub

    surfac

    e)

    meth

    ane/etha

    ne

    (surfacelakes

    )

    nitrog

    en(su

    rface)

    nitrog

    en(su

    bsurfa

    ce)

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    Suggestions to search forhabitability conditions elsewhere?

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    Carbon based, DNA-like search, in planetary systems

    Targeting small constituents of organic compounds Radio/IR/

    X (Pilling et al., A&A 2005)

    Targeting PANHs IR (Hodges et al., ApJ 2005)

    Other alternatives (chemical/physical/meteorological)

    Other liquids/fluids demand a different chemistry (not CHON

    based) due to thermodynamical requirements (Bains,

    Astrobiology 2005).

    Self-sustained ability to disturb a local environment

    (Atmosphere search for upcoming space missions).

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