<p>I believe that alien microorganisms may be abundant throughout the universe.</p>
<p>I believe that the probability of there being intelligent life is actually far smaller than what many people think (you need a single certain-sized star with a certain-sized planet a specific distance away, a Jupiter-like planet close enough to diminish the probability of being hit by an asteroid, a moon to stabilize the planet, etc. etc.). I second the notion that Drake’s Equation is utterly useless and full of BS. </p>
<p>While I may believe that the probability of there being intelligent life may be low, I do not think it is equal to zero. However, I do not think that Star Wars-esque galactic empires are likely to exist. </p>
<p>I’m almost positive that aliens haven’t visited Earth. Based on my belief on a small number of intelligent aliens, if any, and the fact that there are only between 100 and 400 billion stars in our galaxy which is 100,000 light years across, 1000 light years deep and thousands to millions of light years away from the nearest galaxies, I conclude a very low probability that aliens have ever visited Earth.</p>
<p>Generations of aliens would need to live and die on a spacecraft capable of traveling near the speed of light. Imagine this: you’ve lived your entire life on a spaceship, along with your father, grandfather, and great-grandfather. What do you when you finally reach a life-supporting planet? Kidnap a few people, surprise some pilots, and make a couple of crop circles. Wonderful.</p>
<p>The idea that past cultures have been visited by aliens is equally ill-founded in my opinion. The only reason for believing that aliens may have visited is that we cannot currently explain how certain tools and structures were created. Remember how people used to think that storms and volcanic eruptions were caused by angry gods? Same line of thought.</p>