Origin of life and detection of bio-signatures in our solar systel - Zita Martins

Zita Martins - Royal Society University Research Fellow, Imperial College London

Lundi 3 novembre 2014 à 14 h 30

IMPMC - Site Buffon - 61, rue Buffon, Paris 5e

Salle des élèves - 2e étage

Abstract

The origin of life on Earth is one of the biggest scientific questions waiting to be answered. It may have had a contribution from endogenous and/or exogenous sources, with the most theories suggesting the presence of water and a continuous supply of prebiotic organic compounds as a requirement. The first experimental analysis on the abiotic formation of the building blocks of life was performed in 1953 by Stanley Miller, who synthesised organic compounds using a spark discharge in a mixture of reduced gases. Although this was a ground breaking result, it was later shown that the atmospheric conditions used in this experiment did not correspond to the ones of our primitive planet. As the Earth was heavily bombarded by comets, asteroids, meteorites and interplanetary dust particle (IDPs) 4.6 to 3.8 billion years ago, the exogenous delivery of organic compounds is an alternative.  Comets contain some of the building blocks of life and their precursors, and the impact of comets and asteroids into the Earth may have also led to the formation of organic molecules. In addition, a class of meteorites named carbonaceous chondrites have a rich organic inventory, containing several building blocks of life in its soluble fraction. As future space missions will investigate the possibility of past and/or present extra-terrestrial life, it is important to determine how life may have originated in other places of our solar system, and how to detect possible bio-signatures. This talk will discuss how the study of meteorites, asteroids, comets and Mars soil analogues is used to investigate the origin of life on Earth and how to detect any possible signatures of extra-terrestrial life in our solar system.