Impacts and life

  • Datum: –15.00
  • Plats: Online: Zoom
  • Föreläsare: Magnus Ivarsson, Naturhistoriska riksmuseet
  • Arrangör: Avdelningen för astronomi och rymdfysik, institutionen för fysik och astronomi
  • Kontaktperson: Sofia Ramstedt
  • Seminarium

Impact generated hydrothermal systems are thought of as environments favourable for deep microbial life as long as the impact-induced hydrothermal systems are active, which can be from a few thousands up to a million of years, depending on the size of the impact. Recent research at the Swedish Siljan and Lockne craters, respectively have, however, showed that the impact craters sustain deep microbial life hundreds of millions of years after the impact-induced hydrothermal system has ceased. These crater-related microbial communities are based on heterotrophy and obtain necessary carbon and energy from hydrocarbons migrating in the impact-induced fracture system. Methane emission from Martian craters shows that hydrocarbon cycling occur in extraterrestrial craters as well, and suggest this can be an interplanetary phenomenon. I will describe the latest results from drilling and sampling at the Siljan crater, and how we now combine geochemical, paleobiological and microbiological approaches to understand life at depth in craters. These new results challenge the traditional concept on life´s duration in impact craters, and suggest a change of view of impacts as long-lived biological systems.