Presentation on theme: "1 Biomarkers in terrestrial planet atmospheres Super-Earths & Life a fascinating cross-disciplinary puzzle Lisa Kaltenegger MPIA/Harvard University IAUS276,"— Presentation transcript:
1 Biomarkers in terrestrial planet atmospheres Super-Earths & Life a fascinating cross-disciplinary puzzle Lisa Kaltenegger MPIA/Harvard University IAUS276, Oct 15, 2010
2 The Pale Blue Dot Voyager image, 4 billion km away
3 a dot of light = astronomy We will never know how to study by any means the chemical composition of stars Auguste Comte (1835)
4 RV & Transits : density Torres 2008 Fortney, 2007 Sasselov 2007 Zeng & Sasselov (in press)
6 Signs Of Life On An Earth-like Planet Vegetation ? Plant product Surface features e.g. Plant life Bacteria observed Water Oxygen Carbon dioxide Methane Nitrous oxide Ozone Needed for life Primordial; & bacteria product
8 Visible spectrum of Earth Observed Earthshine, reflected from dark side of moon. Ref.: Kaltenegger et al 2007, ApJ 574, 2007 see also e.g.: Montanez-Rodrigez 2005, 07, Arnold 2002, 06, 09; Turnbull 06 Rayleigh Ozone O 3 Chlorophyll ? Oxygen O 2 Water H 2 O
16 Kaltenegger & Traub ApJ 2009 Palle et al. Nature 2009 Data: ATMOS B. Irion 2002 Earth Primary Transit: collect transmitted starlight SNR = N 1/2 (tot) * 2 R p h / R s 2 2002/2014+ ?
17 Earth: ATMOS-3:Transmission validation in far-IR ATMOS-3 transmission of sunlight through Earth’s atmosphere, measured with a fast FTS on Shuttle yellow = model Fit is close, but line wings are not perfect, perhaps owing to line- mixing effects in strong bands. Note low transmission below 10 km.
35 Wade Henning, Harvard, EPS Roger Fu, Harvard, EPS Sarah Rugheimer, Harvard, Astroph. Leah Kilvert, Un. Victoria, Astroph. Exo-P = current students OPEN (AAS job registry): 2 Postdoc & 1 PhD pos MPIA Heidelberg
36 Science Case: ELT,GMT,TMT, JWST (SPITZER, SPICA, SMALL SPACE MISSIONS (e.g TESS) ) Are there other worlds like ours? Epicurius (c. 300 B.C) 2300 years and counting.... Let‘s find out Not just FIND... (POS VIEW ) Characterize rocky exoplanets - composition 0 – 20 years - habitability 5 – 20 years - stage of evolution 5 – 30 years - geochemical cycles 5 – 20 years - HR Diagram of planets 5 – 20 years
38 Summary First potentially Habitable Super-Earth found JWST, ELT/GMT/TMT & new small missions Models: - instrument design, data analysis - explore the underlying physics Earth: a rosetta stone for exoplanets Credit NAI, Harvard Origins of Life
39 Super Earth around M star HZ Gl 581d: Earth Atmosphere, 2.63 bar, 1.8x Earth gravity Tidally locked planet (rapidely rotating planet comparison line (shown in grey)) Scenario 1: high heat transport from day (60%) to night side (40%) CO 2 O3O3 CH 4 H2OH2O CO 2 Kaltenegger, Segura, Mohanty ApJ sub (ApJ)