it would be beyond improbable for the earth to be the only location of life in the entire universe. i dont think anyone (including myself) can really even fathom the sheer magnitude (a definite understatement) of what the universe really is. I mean, think about it, the next closest star to our sun, alpha centauri, is 5 lightyears away. the length of the milky way galaxy is almost 100,000 lightyears across. the andromeda galaxy is over 2 million lightyears away. we wont even be able to see the edges of the universe for billions more years because that is the amount of time it will take for the light to reach us from there. to think that we are the only location of life in the universe is purely self centered. life, in my opinion, undoubtedly exists in thousands, maybe millions, or even billions of locations in the universe. the statistical odds that no where else in the universe exists a mass of rock and water 100 million miles away from a star similar in size to our sun is virtually zero. there are quadrillions (maybe more, well never know) of stars out there and i personally dont see how anyone could think that this is the only place where the conditions have all come together perfectly.