Odds are an important varible in this possibilty of alien life. The trillions and trillions of stars some of which are similar in size to our own with orbiting planets one of which that could be orbiting a star at the right distance to support life. It has to be acknowledged as a possibility. Tau Ceti is the same type of star as our own, it also has the same characteristics as far as mass, energy expended etc... So now with the detection of these radio tranmissions the possibilities of alien life form s has to be considered. There are just too many stars out there for some kind of life to not be present other than our world.