A personal perception of a superb Conference Pathways towards habitable planets Pierre Léna Université Paris Diderot & Observatoire de Paris Pathways towards habitable planets - Barcelona - Sept , 2009

2 What is exoplanet science ? 1.A multi-disciplinary domain, expanding ; 2. A multi-techniques domain, highly creative (coronography) observation : ground + space ( ~ years) ; modelisation, theory, simulation ; 3.A many parameters context, changing fast ( Param ~ 1-2 years) : e.g. plate tectonics, climate & orbit, chemistry, migration…more to come…

3 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 (H 2 O 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

4 Space missions 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 : Necessary step towards the final goal ? Complementarity with ground (RV, interfero,corono…) ? How to best pursue COROT, KEPLER, HST Complementarity of the choices done by national agencies is essential, with crossed (minority) participations whenever possible

5 Space missions : fully characterizing a set of S and 1.Statistical analysis (step1), targets designation (step 2) and partial caracterization (step 3) well under way : COROT, KEPLER, RV (visible, IR for M ) ; Continued with PLATO, TESS…(all Galaxy) ; Keep exploring the full planet mass spectrum (global picture) ; Keep exploring the global Galaxy picture : Microlensing, EUCLID ; 2.Astrometry (SIM) can identify a complete set of (step 2), with ground support (RV, VLTI/PRIMA) = highly recommended;

6 Space missions : 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 ( 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. 4.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 ;

7 Too early to fully define an international flagship mission for ?

8 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 ;

9 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

10 Building-up an international community coherent with the goal and its importance some suggestions 1.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 ; 3.With China, India, Russia (Oparin) : Contributing to the emergence of a community ; Establishing progressive collaboration programs (TMT…) ;

11 Special thanks to the City of Barcelona and to the organizers Thank you for your patience Open for discussion !