The search for a second lineage of life

“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” – Arthur C. Clarke

Life on Earth: –Based on carbon –Requires water –Needs a source of energy –Feeds on negative entropy –Utilizes information –A single shared lineage of inherited DNA What is life?

N = R * f P n e f L f i f C L –N is the number of communicative civilizations –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges –f i is the fraction where intelligence appears –f C is the fraction that develops an interstellar communication capability –L is the lifetime of that civilization in the communicative state The Drake equation

N = R * f P n e f L f i f C L Increasing uncertainty –N is the number of communicative civilizations –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges –f i is the fraction where intelligence appears –f C is the fraction that develops an interstellar communication capability –L is the lifetime of that civilization in the communicative state The Drake equation

N L = R * f P n e f L –N L is the number of lineages of life –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges A modified Drake equation

N L = R * f P n e f L –N L is the number of lineages of life –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges A modified Drake equation

N L = R * f P n e f L –N L is the number of lineages of life –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges A modified Drake equation

N L = R * f P n e f L –N L is the number of lineages of life –R * is the star forming rate –f P is the fraction of stars where planets form –n e is the number of planets that are habitable –f L is the fraction where life emerges A modified Drake equation ~

Likelihoods of: –Creation of organic molecules –Concentration of organic molecules –Combination of organic molecules into amino and nucleic acids –Concentration of chiralities –Emergence of self replicating molecules –etc. Uncertainties in f L

Much research has gone into better constraining the many uncertainties in f L –Difficulties with devising lab experiments Search for extraterrestrial intelligence (SETI) –Finding evidence for just one other lineage of life would add enormously to our ability to estimate f L Constraining f L

Where do we look? –Limiting factors of habitability How should we search? –Potential methods and tools Finding a second lineage

Where do we look? –Limiting factors of habitability How should we search? –Potential methods and tools Finding a second lineage

Thanks for you attention Questions?