Part II
  Tuesday 14 July
  14:40-14:55 	
  
  False positive biosignatures on habitable planets around M dwarfs 	
  
  Sonny Harman
  (PennState, USA) 
  
  M dwarfs account for the majority of stars in our galaxy, and are more likely
  to have terrestrial planets in their habitable zones than more massive stars.
  Taken together, these two facts make habitable planets around M dwarfs the
  most likely targets for near-future characterization in the search for life
  around other stars. This is likely to be complicated by the radiation
  environment throughout the lifetime of the planet. For example, some authors
  have suggested that M star planets will experience rapid water loss and
  develop O2-dominated atmospheres long before the star evolves onto the main
  sequence. Other authors have put forward that a CO2-dominated atmosphere could
  be dissociated, leading to a substantial (and potentially detectable) amount
  of O2. If so, the presence of O2, long considered a robust biosignature, would
  be a false positive in the search for life. This talk will focus on O2 as a
  biosignature, as well as the implications for other suggested biosignature
  gases, for planets orbiting M stars.