IAU Symposium 345:
Origins: From the Protosun
to the First Steps of Life

August 20 – 23, 2018


Scientific Rationale:

This symposium explores the chain of events that could have been involved in the formation of the Earth and the earliest lifeforms. Many steps in this process have been inferred already from detailed observations and computer models. Stars form in dense interstellar clouds and are usually clustered among other stars. The environment of the early Sun should have been affected by that clustering, as suggested by peculiarities in the isotopic composition of meteorites. Protoplanetary disks that may form Earth-size planets have been studied at high resolution using interferometric techniques in infrared and radio wavelengths. These observations reveal the chemistry and dust content of the disks, and possible interactions with the growing planets. While there are no direct observations yet of Earth-size protoplanets, there is evidence for Earth-sized planets around other stars, and there are clues to the formation process of the Earth itself from within our Solar System. The conditions for habitability are more difficult to observe and model. How these conditions arose and the nature of the first organisms are topics of intense study in many fields. The purpose of this symposium is to bring together researchers in these fields so that each component of our origins story can motivate and illuminate the others, while giving a concise summary of the current state of knowledge for the next generation. The approaching availability of large new observatories will provide an unprecedented opportunity to explore our origins even further.


  • The galactic environments of the Earth and Sun
  • Formation of solar-type stars and the Sun
  • Formation and evolution of protostellar disks
  • Physical and chemical conditions in the proto-solar nebula
  • Protoplanetary disks as factories of organics and volatiles
  • Planetary systems around solar-type stars
  • Toward building true Earth analogs
  • Interactions between the central star & atmospheres of Earth-like planets
  • Conditions on the early Earth, including geophysical processes
  • Steps toward habitability & early forms of life



Monday, 20. Aug.

Star Formation in the solar neighborhood
room: C
10:30 - Juvela, Mika (Star Formation in the solar neighborhood – surveys, generalities, simulations)
11:00 - Cunningham, Maria (The role of automated methods for filament finding in understanding the complex relationship between filaments, magnetic fields and star formation)
11:15 - Großschedl, Josefa Elisabeth (Resolved Maps of Star Formation Rate and Efficiency for the GMC Orion A)
11:30 - Nguyen-Luong, Quang (The dense galactic environments of the Milky Way)
11:45 - Melnik, Anna (Kinematics of OB-associations in the 3-kpc solar neighborhood)

Star formation in cloud cores
room: C
13:30 - Federrath, Christoph (Star formation in cloud cores – simulations and observations of dense molecular cores and the formation of solar mass stars)
14:00 - Hacar, Alvaro (ALMA observations of the Orion Integral Filament: evidence for fibers in a massive cloud)
14:15 - Küffmeier, Michael (Accounting for the protosolar environment)
14:30 - Kruijssen, Diederik (The implications of clustered star formation for (proto)planetary systems and habitability)
14:45 - Stephens, Ian (MASSES: An SMA Large Project Surveying Protostars to Reveal How Stars Gain their Mass)


Tuesday, 21. Aug.

Early environment of the pre-solar nebula
room: C
10:30 - Young, Edward (The birth environment of the solar system constrained by the relative abundances of the radionuclides)
11:00 - DWARKADAS, VIKRAM (Triggered Star Formation inside the Shell of a Wolf-Rayet Bubble as the Origin of the Solar System)
11:15 - Fujimoto, Yusuke (Short-lived radioisotopes in meteorites from Galactic-scale correlated star formation)
11:30 - Fehér, Orsolya (Episodic accretion in focus: revealing the circumstellar environment of FU Orionis-type stars with millimeter interferometry)
11:45 - Maury, Anaëlle (Characterizing the youngest protostellar disks with the IRAM-PdBI and ALMA: large Class 0 disks are rare)

Formation and evolution of protoplanetary disks
room: C
13:30 - Perez, Laura (Formation and evolution of protoplanetary disks – observations and modeling of jets, disks, and disk substructures)
14:00 - Bai, Xuening (Towards Realistic Understandings of Gas Dynamics in Protoplanetary Disks)
14:15 - Bjerkeli, Per (Resolving star and planet formation with ALMA)
14:30 - Oya, Yoko (Unified Picture of Chemical Differentiation in Disk-Forming Regions of Low-Mass Protostellar Sources)
14:45 - Stapelfeldt, Karl (A Planetary Mass Companion in an Edge-on Protoplanetary Disk System)


Wednesday, 22. Aug.

Physical and chemical properties of protoplanetary disks
room: C
10:30 - Kamp, Inga (Physical and chemical properties of protoplanetary disks)
11:00 - Flock, Mario (3D radiation MHD simulations of gas and dust in protoplanetary disks)
11:15 - Varga, Jozsef (A mid-infrared interferometric survey of the planet-forming region around young Sun-like stars)
11:30 - Jorgensen, Jes Kristian (New insights into the complex chemistry of young stars from the ALMA PILS survey)
11:45 - Pignatale, Francesco (The first 200 kyr of the Solar System)

Formation of Earth and Earth-like planets
room: C
15:30 - Kokubo, Eiichiro (Formation of terrestrial planets)
16:00 - Broz, Miroslav (Dynamics of protoplanets embedded in gas/pebble disks and its complex dependence on parameters)
16:15 - Ipatov, Sergei (Formation of the Earth-Moon system)
16:30 - Chaparro, Germán (Transitional disk archaeology from exoplanet population synthesis)
16:45 - Poster Talks


Thursday, 23. Aug.

Early planetary atmospheres and surfaces
room: C
08:30 - Breuer, Doris (Early planetary atmospheres and surfaces, origin of the Earth’s water, crust and atmosphere)
09:00 - Marov, Mikhail (Water inventory from beyond the Jupiter orbit to the terrestrial planets and the Moon)
09:15 - Rice, Thomas (Exploring the Origins of the Earth’s Nitrogen)
09:30 - Shematovich, Valery (Neutral atmospheric escape in the Solar and extrasolar planetary systems)
09:45 - Iro, Nicolas (Modelling the atmosphere of habitable planets)

Early conditions on the Earth
room: C
10:30 - Lammer, Helmut (Constraining the early evolution of terrestrial planets by reproducing elemental ratios)
11:00 - Valio, Adriana (The biological impact of superflares on a planet in the Habitable Zone)
11:15 - Lüftinger, Theresa (Stellar activity and winds shaping the atmospheres of Earth-like planets)
11:30 - Abraham, Peter (Outbursts of young Sun-like stars may change how terrestrial planets form)
11:45 - Wandel, Amri (Bio-habitability and life on planets of M- to G-type stars)

Earth-like planets
room: C
13:30 - Apai, Daniel (The characterization and properties of Earth-like planets)
14:00 - Berdyugina, Svetlana (Biohaze as an atmospheric biosignature of an early Earth)
14:15 - Starchenko, Sergey (Critical and ordinary hydrodynamic and magnetism of planetary interiors)
14:30 - Pye, John (Exoplanet host-star properties: the active environment of exoplanets)
14:45 - Poster Talks

Early life on Earth
room: C
15:30 - Pross, Addy (Early life on Earth – tracing the physical/chemical process from non-living to living)
16:00 - Pacheco, Eduardo (Unveiling the whole from its parts. Or to see the forest from the trees)
16:15 - Taubner, Ruth-Sophie (Simulating putative Enceladus-like conditions: The possibility of biological methane production on Saturn’s icy moon)
16:30 - Scherf, Manuel (Earth’s paleo-magnetosphere and its implications on the evolution of the terrestrial atmosphere)
16:45 - Abrevaya, Ximena C. (Towards Astrobiological Experimental Approaches to Study UV Surface Environments: From the Early Solar System to Exoplanets)



  • Yuri Aikawa (Japan)
  • Bruce Elmegreen (USA, co-chair)
  • Muriel Gargaud (France)
  • Manuel Guedel (Austria, co-chair)
  • Nader Haghighipour (USA, co-chair)
  • Lucyna Kedziora-Chudczer (Australia)
  • Susana Lizano (Mexico)
  • Morris Podolak (Israel)
  • Monica Rubio (Chile)
  • L. Viktor Tóth (Hungary, co-chair)



Bruce Elmegreen 


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