Does Alien Exists?

We all have heard of aliens but we exactly don't know weather do they really exists or not? But it is fact that they do exists as we do.Aliens are those creatures that live beside our planet.They may be well civilized and they may be more developed than us and may be more primitive than us.There are many people who are said to have seen LIFO and aliens too,but exact proof has not been obtained.However we all know aliens do exists.
Is Life Elsewhere Impossible?
On the other side of the “Do Aliens Exist?” question is the rare earth hypothesis. In the 1995 book, The Creator and the Cosmos, physicist Hugh Ross lists 33 characteristics a planet must have to support life. He estimates the probability of such a combination to be found in the universe as “much less than one in a million trillion.”
In their 2004 book, The Privileged Planet, astronomer Guillermo Gonzalez and theologian Jay Richards carry the notion further, asserting that our place in the cosmos is not only special but also designed for discovery.