Formation of life on other Planets
Issues with the post

I agree that the question is too broad. It is not the only issue, it is also primarily opinion-based (see below for explanations). The post is also somehow unclear (see below for explanations). But here is some kind of an answer that may help you.

If you google your question you will get tons and tons of hits. There is a whole lot of videos on youtube that address this question. You may want to have a look at those and come on StackExchange to ask a more accurate question because for the moment the question is too broad.

As a first short answer to the questions...


  At the present time it looks as if there is no other life in the Universe other than here on Earth


It sounds wrong (as a consequence your question would be primarily opinion based). We haven't found life. This doesn't mean that life doesn't exist elsewhere. Actually most people think that life exist elsewhere. Part of the issue behind this question is the definition of life. Often, people refers to Drake equation (you might want to read about it) which gives you the number of planets where life should exist. However, Drake equation is a speculation that has no solid grounds. It is actually pretty complicated (or impossible because we need to assume things about what the original conditions are) to calculate a probability that life occurs on a given planet. While it sounds pretty intuitive to many people (me, including) that life should exist somewhere else, there is really not much certainty.


  Is it possible for something to happen only once?


Well....yes, the death of Napoleon occurred only once.... I am not quite sure what you mean with this question, it is unclear.