Please note the different location for this Exoplanet Tea.

Paul Rimmer from Cambridge University in the UK is visiting us Wednesday to present the Exoplanet Tea talk. Paul is a postdoc working with Didier Queloz and John Sutherland, and his expertise ranges from theoretical studies of exoplanet atmosphere to laboratory studies of origins-of-life chemistry. On Wednesday, Paul will tell us about how active M-dwarfs might be very compelling astrobiological targets.

Abstract: Given that the building blocks of life were produced via ultraviolet (UV) photochemistry, we try to constrain on which rocky planets this same photochemistry is most likely to take place. We do so by examining two key reactions that have been discovered in the lab to lead from the reactants (HCN and an anion) to RNA precursors. In the dark, however, these reactants form durable adducts that do not lead to the synthesis of RNA precursors. We measure the rates of the reactions in the light (‘light chemistry’) to the reactions in the dark (‘dark chemistry’) to quantify how much UV light is necessary for the formation of these building blocks. This estimate allows us to carve out an ‘abiogenesis zone’, outside of which the building blocks of life are not likely to form photochemically on the surfaces of rocky planets. Our results suggest that for the building blocks of life, hotter is better. Quiet M dwarfs do not produce the required amount of ultraviolet light for the formation of life’s building blocks, but active M dwarfs may. In this talk, I explore the ‘brighter side’ of active cool stars for the prospects of life on the rocky worlds that they host.