Organic Matter in the Universe: from solar system to distant galaxies

Recent observational and experimental evidence for the presence of complex organics in space is reviewed.  Remote astronomical observations have detected ~200 gas-phased molecules through their rotational and vibrational transitions.  Many classes of organic molecules are represented in this list, including some precursors to biological molecules.  A number of unidentified spectral phenomena observed in the interstellar medium are likely to have originated from complex organics.  The observation of these features in distant galaxies suggests that organic synthesis had already taken place during the early epochs of the Universe.  In the Solar System, almost all biologically relevant molecules can be found in the soluble component of carbonaceous meteorites.  Complex organics of mixed aromatic and aliphatic structures are present in the insoluble component of meteorites.  Hydrocarbons cover much of the surface of the planetary satellite Titan and complex organics are found in comets and interplanetary dust particles.  The possibility that the early Solar System, or even the early Earth, have been enriched by interstellar organics is discussed.



  • Kwok, S. The Synthesis of Organic and Inorganic Compounds in Evolved Stars, Nature, 430, 985 (2004)
  • Kwok, S. and Zhang, Y.  Mixed aromatic/aliphatic organic nanoparticles as carriers of unidentified infrared emission features, Nature, 479, 80 (2011)
  • Kwok, S. Complex organics in space: from Solar System to distant galaxies, A&A Rev., 24, 1-27 (2016)
Sun Kwok (The University of Hong Kong)
Speaker Introduction: 

Prof. Sun Kwok is the Director of Laboratory for Space Research and Chair Professor of Space Science at The University of Hong Kong (HKU).  He has previously served as Dean of Science at HKU, Director and Distinguished Research Fellow of the Institute of Astronomy and Astrophysics, Academia Sinica, and professor of astronomy at the University of Calgary.  His recent books include Stardust: the Cosmic Seeds of Life (Springer, 2013), Organic Matter in the Universe (Wiley, 2011), Physics and Chemistry of the Interstellar Medium (University Science Books), Cosmic Butterflies (Cambridge, 2001), The Origin and Evolution of Planetary Nebulae (Cambridge, 2000).  He has served as President of Commission 34 (Interstellar Matter) and is the current President of Commission F3 (Astrobiology) of the International Astronomical Union.

KIAA-PKU Auditorium
Luis Ho
Thursday, February 23, 2017 - 4:00pm