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Evolution of the universe: From Astrophysics to Astrobiology. FROM CHEMICAL EVOLUTION ON EARTH TO INSTRUMENTATION ISSUES FOR TESTING SYSTEMS ASTROBIOLOGY ON EXO-WORLDS International Workshop on Chemical Evolution and Origin of Life. ITT Roorkee, 21 – 23 March 2013. Julian Chela-Flores
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Evolution of the universe: • From Astrophysics to Astrobiology FROM CHEMICAL EVOLUTION ON EARTH TO INSTRUMENTATION ISSUES FOR TESTING SYSTEMS ASTROBIOLOGY ON EXO-WORLDS International Workshop on Chemical Evolution and Origin of Life. ITT Roorkee, 21 – 23 March 2013. Julian Chela-Flores The Abdus Salam ICTP, Trieste, Italia and Instituto de Estudios Avanzados, Caracas, Republica Bolivariana de Venezuela The Origins: how, when and where it all started, Accademia Nazionale dei Lincei. Centro Linceo Interdisciplinare “Beniamino Segre”, Roma, 22 May 2006 A. B. Bhattacherjee 1, J. Chela-Flores 2 and S. Dudeja 3 1. Department of Physics, ARSD College, University of Delhi, New Delhi, India 2. ICTP, Trieste and IDEA, Caracas, Bolivarian Republic of Venezuela • 3. Department of Chemistry, ARSD College, University of Delhi, New Delhi, India
Life on exoworlds The Earth-like worlds (ELWs: planets and exomoons)
Relative sizes of dwarf stars MV3: Gliese 581 GV5: Kepler 22
Orbital period The habitability zone of red dwarfs is indeed closer to the star
Orbital period 1 year less transits contrast less favorable 10-25 days more transits, contrast more favorable for the present observations (Kepler), as the habitability zone is closer to the star
Preliminary parameters of ELWs Transits from the Kepler Mission Kepler: ELW from transits
or their Habitable Exomoons (or exomoon) Probing exoatmospheres will be possible with the Kepler successors: (a) future missions and (b) future instrumentation
Future Missions: ESA’s Exoplanet Characterisation Observatory (EChO) NASA’s Fast INfrared Exoplanet Spectroscopy Survey Explorer (FINESSE) NASA’s Transiting Exoplanet Survey Satellite (TESS)
Future instrumentation James Webb Space Telescope The Giant Magellan Telescope
Systems (astro)biology • Systems biology is used in biomedical research, but in our case of systems of ELWs, we single out perturbations to exoatmospheres, due to autochthonous biological processes producing anomalous abundances of oxygen. • With sufficient data from Kepler successors models of systems (astro)biology will describe the structure of the systems (ELWs) and their response to perturbations. • The expected perturbations would be due to biologic communities that shift the primary non-biogenic mixture of CO2, N, a small fraction of O2, water into oxygenic atmospheres.
The Great Oxidation Event (GOE) in the habitability zone of the solar system
An analytic model Assumptions: • We assume the universality of biology. • In particular, we assume evolutionary convergence.
The analytic model Parameters • The current and starting abundance of biogenic gas (oxygen) and non-biogenic gas (carbon-dioxide) in an ELW of the red dwarf. • The luminosity of the ELW, the luminosity of the Sun, t the current time, and t0 is the time at which biogenic gas started forming in substantial amount on Earth. • In the expression for CO2we have an additional parameter taking into account that not all of it will be converted into O2 (other processes such as photorespiration will generate some additional CO2).
The analytic model Allows a prediction for: • A GOE in an ELW orbiting a red dwarf. • The abundance of the non-biogenic gas in an ELW orbiting a red dwarf. • It suggests resetting the origin of time at the big bang.
Preliminary results ELWs orbiting a red dwarf
Fraction of non-biogenic gas ELWs orbiting a red dwarf
Worlds around red dwarfs Much older than the Earth? Credit: Dressing& Charbonneau
An exoplanet older than Earth Orbits around red dwarfs
Habitability could have preceded terrestrial life • Our own tiny Kepler environment is less than 300 light years. • With SETI the cosmic environment accessible by2020 should be about three times the Kepler range, about 1000 light years.
Additional instrumentation issues (further insights from the neighbouring moons) Not incorporated in the JUICE payload JUICE Chela-Flores, 2010, Int. J. Astrobiol.
Summary • Most stars are red dwarfs and some host Earth-like planets. • Oxygen and carbon dioxide are the exo-bioindicators considered in this work. • Model predictions for exo-atmospheres have assumed: • Universal biology (evolutionary convergence) • Testing the predictions for the exoatmospheres of ELWs is possible with forthcoming new missions and with future Earth-bound instrumentation.