capable of sustaining life that actually evolve life * fi is the fraction of those planets where live has evolved that evolve intelligent life * fc is the fraction of planets with intelligent life that develop the capability to communicate * L is the fraction of the planet's life during which the intelligent life can communicate 0.3 to 1 of these possible stars are created in the milky way every year, and the eventuall outcome is still large in the orion (our) arm of the galaxy alone It is purely human nature for us to be as short-sighted as to think that we are all that exist in terms of intelligent life. Did you know, for example, that deep inside caves in Mexico, in an atmosphere made up of such a high concentration of Hydrogen Sulphide that it is impossible for humans to enter without proper protective and breathing equipment, there are microbes living and breeding, with no need for oxygen, sunlight or any other "traditional" conditions thought to be ideal for living organisms except... water. Likewise, micro-organisms have been found living in communities around underwater volcanic vents, where temperatures exceed 450 degrees Centigrade. It seems we may have assumed a little too much when looking for life on other planets, and instinctively turned to Mars at first, since it is our neighbour. It appeared that the planet was and may have always been barren, but there is evidence that it may have, or indeed may still harbour life. Deep