A personal perceptionof a superb Conference

Pathways towards habitable planets

Pierre Léna

Université Paris Diderot & Observatoire de Paris

Pathways towards habitable planets - Barcelona - Sept. 15-18, 2009

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What is exoplanet science ?

1. A multi-disciplinary domain, expanding ;

2. A multi-techniques domain, highly creative (coronography)

• observation : ground + space ( ~ 10-20 years) ;

• modelisation, theory, simulation ;

1. A many parameters context, changing fast • (Param ~ 1-2 years) : e.g. plate tectonics, climate & orbit,

chemistry, migration…more to come…

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The goal and the steps to reach it

1. Statistical occurrences ;2. Designation of targets suitable for spectroscopy ;3. Characterization ;

• Physical and chemical conditions on solid/liquid surface and atmosphere ;

• Maximum information on the system (star, age, other planets…)

Characterize a set of habitable planets (H2O liquid) = image + extended spectral analysis = nearby (10 pc)A set : Earth twins (, G) or mass distribution 1-10 M ?

Darwin proposal (1993) was prophetic and played a great role

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Space missions 2010-2020

1. On the way : GAIA, JWST

2. Choices to be made (500 M€ to 1 G€) : • USA : Decadal review, NASA choices ;

SIM-Lite, FKSI, TESS, THESIS, EUCLID-Microl., + ASMCS (7)…• Japan : SPICA• ESA : CV1 PLATO, CV2 SEE-COAST + …

3. Criteria : 1. Necessary step towards the final goal ?

2. Complementarity with ground (RV, interfero,corono…) ?

How to best pursue COROT, KEPLER, HSTComplementarity of the choices done by national agencies

is essential, with crossed (minority) participations whenever possible 

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Space missions 2010-2020 : fully characterizing a set of S and

1. Statistical analysis (step1), targets designation (step 2) and partial caracterization (step 3) well under way :

1. COROT, KEPLER, RV (visible, IR for M) ;2. Continued with PLATO, TESS…(all Galaxy) ;3. Keep exploring the full planet mass spectrum (global picture) ;4. Keep exploring the global Galaxy picture : Microlensing, EUCLID ;

• Astrometry (SIM) can identify a complete set of targets @10pc (step 2), with ground support (RV, VLTI/PRIMA) = highly recommended;

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Space missions 2010-2020 : fully characterizing a set of Super and

3. Transit (+ off-transit) from space is probably the best next choice for spectroscopic characterization (step 3) = pointed spectrophotometry

• Broad spectral coverage (0.5-20 m or more) is necessary (ambiguities) ;• JWST may not do it sufficiently (observing time, S/N ratio ?) ;• Enough targets ; feasibility proven ; direct comparison with models ;

• M-class mission(s) (500 M€ ?) to be planned (ESA, NASA) ;• Extends the VLT, ELT towards Super masses.

• Coronography and IR interferometry (imaging) progressing rapidly, on the way to become fully convincing (exozodi..) for reaching the goal ;

• SPICA + A possible Probe mission to solidify the concepts ;• Double blind study ;• JWST : many lessons to be learned ;

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Too early to fully define an international flagship mission

for 2020-2030 ?

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Ground programs : higher mass, but contributing to the final goal

1. Radial velocities, including IR (M) : HARPS, VLT/ESPRESSO…

2. Instrumentation for 10-m (Keck, VLT, ..) and ELTs • coronography, exAO ;

3. Optical interferometry : • Astrometry : VLTI/PRIMA, • Nulling & Exozodi : KI, LBTI.. • Exozodi : ALLADIN (DomeC)• FITE …

4. Microlensing MOA ;

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Building-up an international community

1. USA : NASA+NSF, NASA ExP Exploration Program, Decadal Review, ExP Science Institute, Sagan Fellows, Exoplanet Forum..;2. Japan : seems well organized (long term program, Subaru synergy) ; 3. Europe

– ESO and ESA (EP-RAT) do not have a common policy analysis ;– ASTRONET (EU Funded review, 2008) not really Exoplanet (8 pages/126)

ASTRONET Recommandations

– High contrast and high-resolution IR interferometer in space ;– High-precision photometry (< 0.01 mag) from space+ ground robotic;– High spectral resolution, near to far IR, on ELT with AO;– Next generation of 0.1 m/s RV instruments

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Building-up an international communitycoherent with the goal and its importance

some suggestions1. Globally. Initiating a Barcelona process may mean :

• A regular Pathways Conference (3 years ?) ;• An identified place for permanent interactions : ICTP model… ?• A dedicated, long-term action for outreach (HST model) ;• Pursue the « broad » analysis : epistemological, ethical … ;

2. For Europe, specifically :• A permanent Committee representing the community ;

1. Presenting the Goal to the EU and getting support (FP8) ;2. Recognized by ESA and ESO ;

• A dedicated Fellowship program (name ?)• Implementing the Barcelona process in Europe ;

• With China, India, Russia (Oparin) : • Contributing to the emergence of a community ; • Establishing progressive collaboration programs (TMT…) ;

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Special thanks to the City of Barcelona and to the organizers

Thank you for your patience

Open for discussion !