Drake equation?

10/5/14  

1  

Drake  Equa*on  –  Day  2  

N = R★ fp ne fl fi fc L

ARE  WE  ALONE  IN  THE  UNIVERSE?   The  Ques*on  

10/5/14  

2  

The  First  Two  Factors—   Part  I  

Based  on  your  research,  address   the  following  ques<ons:  

•  The  structure  of  the  universe   –  what  does  it  contain?  

•  How  many  stars  are  in  our   galaxy;  the  Milky  Way   galaxy?  

•  The  rate  of  star  forma*on   in  our  galaxy?  

N = R★ fp …

The  First  Two  Factors—   Part  II  

  •  What  frac<on  of  stars  is  

appropriate  for  a  stable   planetary  system?  

  •  How  many  exoplanets  

found?  

•  What  is  the  habitable   zone?  

N = R★ fp …

10/5/14  

3  

Based  on  what  we  know  

Es*mate  the  first  two  factors  

The  Number  of  Broadcas<ng  Civiliza<ons  

Reasonable  Values  

N= R ★

fp

(8-20) 10

(0.5-0.99) 0.8

Stars/year  in  M.W.  

Stars  that  form  planets  

The  Next  Two  Factors—Part  I  

  3.  ne  =  the  average  #  of  

planets  in  each  system   that  can  sustain  life  

  4.  fl  =  Life-­‐sustaining  planets  

on  which  life  actually   begins/develops.  

10/5/14  

4  

Before  we  can  discuss  these  two  factors,  we  must  first   examine  two  ques<ons.   1.  What  is  the  defini<on  of  life?    

The  Next  Two  Factors—Part  II  

     What  is  Life?  

Humanoid?   Intelligent?   Self  Reproducing?  

2.  What  are  the  requirements  for  life?  

The  Next  Two  Factors—Part  III  

     And  

10/5/14  

5  

Due  next  week   before  class  via   TurniItIn  on   Moodle.  

Read  ar*cle   posted  on  

Moodle  for  this   week  

Assignment  

It  considers   important  aspects   of  what  life  is  and   the  requirements  

for  life  

It  gives  a   systema<c  way  to   think  about  the   possibility  of  life   “out  there”  

Your  assignment   is  to  make  a  one-­‐ page  summary  of  

the  ar<cle