Colloquia

Venue of the HIFOL colloquia:

Königstuhl 17, Heidelberg: Auditorium of Haus der Astronomie
@
16:15


Coming Colloquia



08.11.2017 – Ralf Kaiser

(University of Hawaii)

Title: "Exploiting Tunable Vacuum Ultraviolet Light to Unravel the Synthesis of Biorelevant Molecules in Deep Space"

Abstract: Kuiper Belt Objects (KBOs) - small planetary bodies orbiting the sun beyond Neptune - emerged in their critical role to understand the chemical evolution of the Solar System and how the molecular precursors to life formed and came together to create environments such as on early Earth. This talk presents novel developments in the understanding of the formation of key classes of biorelevant molecules central to the Origins of Life in ices of Kuiper Belt Objects (KBOs) exploring cutting edge low temperature surface science experiments exploiting soft photo ionization with tunable vacuum ultraviolet light coupled with a time of flight mass spectrometric, isomer selective product detection (PI-ReTOF-MS). By probing for the first time specific structural isomers without their degradation (fragment-free), the incorporation of tunable vacuum ultraviolet photoionization allows for a critical understanding of reaction mechanisms that exist in extraterrestrial ices compared to traditional methods thus eliminating the significant gap between observational and laboratory data that existed for the last decades. Since Rosetta’s lander Philae touched down on 67P/Churyumov–Gerasimenko – a short period comet from the Kuiper Belt - data on the molecular composition of the comet’s surface can be directly compared with the inventory of biorelevant molecules extracted from our experiments thus defining the first inventory of biorelevant molecules, which forms the nucleus for evolution of life in our Solar System billions of years ago. Considering that Kuiper Belts have been observed around stars like Vega outside our Solar System as well, this knowledge can be transferred to extrasolar planetary systems thus revolutionizing our understanding of the origin of cosmic life as we know it and eventually revealing the molecular birthplace of life. Since cometary matter (at least partially) originated from the molecular cloud, which provided the molecular feedstock for our Solar System, these investigations also expose how ubiquitous astrobiologically relevant molecules such as glycolaldehyde, which cannot be formed in the gas phase of the interstellar medium, can be synthesized on ice coated interstellar grains at 10 K via a cosmic-ray initiated non-equilibrium chemistry. With the commission of the Atacama Large Millimeter/Submilli-meter Array (ALMA), the detection of more complex organic molecules in space will continue to grow – including biorelevant molecules connected to the Origins of Life theme - and an understanding of these data will rely on future advances in hard core physical chemistry laboratory experiments ultimately revealing the level of complexity of astrobiologically relevant molecules which can be synthesized in our Universe.


29.11.2017 – Mark van Zuilen

(Institut de Physique du Globe de Paris)

Title: Tracing Life in the early Rock Record

Abstract: Reconstructing the nature and habitat of ancient life is a difficult task that strongly depends on the study of rare microfossils in the early rock record. The preservation of such organic structures critically depends on rapid entombment in a mineral matrix. Throughout the Precambrian the oceans were silica-enriched, leading to the formation of chert deposits that could effectively incorporate remnant microbial cells. As we trace this record of life back in deep time, however, three obstacles are encountered; 1) many microorganisms lack sufficient morphologic complexity to be distinguished from each other and from certain abiologic microstructures, 2) early habitats of life were dominated by hydrothermal processes that can generate abiologic organic microstructures, and 3) the ancient rock record has been metamorphosed causing variable degradation of microbial cells. Overall, we are thus left with an incomplete record of life that becomes increasingly controversial as we study progressively older rocks. In recent years important progress has been made in the development of precise in-situ analytical techniques that enable detailed characterization of individual organic microstructures and their mineral matrices. Here an overview is given of the micron- and nano-scale transformations that occur in microbial materials during silica entombment and prograde metamorphism. Recent results of experimental silicification of microbial cells are presented, followed by detailed studies of preserved cyanobacteria in modern hot spring silica sinters, and carbonaceous microstructures in Early Archean chert deposits. The critical differences will be described between abiologic artefacts such as carbonate-silica biomorphs and true microfossils in hydrothermal cherts. An assessment is made of the potential for tracing life in the oldest, most altered part of the rock record.


Past Colloquia



26.07.2017 - Sebastian Pallmann

(Ludwig-Maximilians-Universität, München)

Title: "Scouting Chemical Networks" Ludwig-Maximilians-Universität, München)


14.06.2017 – Mark Harrison

(University of California, Los Angeles)

Title: "A New View of Early Earth and its Habitability"


03.05.2017 – Frank Postberg

(Institute of Earth Sciences, University of Heidelberg)

Title: "The Search for Life on Icy Ocean Moons in the Solar System"


12.04.2017 – Bernard Marty

(Centre de Recherches Pétrographiques et Géochimiques Vandœuvre-lès-Nancy, France)

Title: "Origin of Water and other Volatile Elements in Inner Planets, in the Light of the Recent Results from the Rosetta Mission"


11.01.2017 – Edwin Bergin

(University of Michigan, Department of Astronomy)

Title: "Tracing the Ingredients of Habitable Worlds from the Interstellar Medium through Planet Formation"


21.12.2016 – Uwe J. Meierhenrich

(Université Nice Sophia Antipolis Institut de Chimie de Nice)

Title: "The Cometary Rosetta Mission: Analytical Chemistry on the Nucleus of Comet 67P"


30.11.2016 – Christian Hallmann

(Max-Planck-Institute for Biogeochemistry, MARUM, University of Bremen)

Title: "Biomarker-hydrocarbon indicators for the early evolution of life on Earth"


16.11.2016 – Albrecht Ott

(Universität des Saarlandes)

Title: "Spontaneous Autocatalysis in a Prebiotic Broth"


05.10.2016 – Bruce Fegley

(Washington University St. Louis)

Title: "Chemical models of Earth's early atmosphere"


01.06.2016 – Peter Schuster

(University of Vienna)

Title: "From Darwin’s Natural Selection to Reproducing Molecular Networks"


18.05.2016 – Ximena C. Abrevaya

(CONICET, Buenos Aires)

Title: "Astrobiology: interdisciplinary approaches for a multidisciplinary science"


11.05.2016 – Paul Higgs

(Origins Institute, McMaster University, Ontario)

Title: "From Chemistry to Biology: How did the RNA World get started?" (Organized by Th. K. Henning) 


06.04.2016 – Farid Salama

(NASA-Ames Research Center, CA, USA)

Title: "Organic Matter in Space" (Organized by Th. K. Henning) 


09.03.2016 – Lisa Kaltenegger

(Associate Professor of Astronomy @ Cornell University and Director of the Carl Sagan Institute)

Title: "Rocky Exoplanets and the Scientific Concept of Habitable Worlds"


10.02.2016 – Ralph Pudritz

(McMaster University Hamilton, Canada)

Title: "Amino acid and Nucleobase Synthesis in Meteoritic Parent Bodies"

Presentation from speakers

>> 2015

 
loading content