The universe is so big it's hard to imagine we're really alone in it. But scientists aren't so pessimistic. They believe that we will find life in space in this century. Let's just hope they're friendly.

"We are going to find life in space in this century." Those are the words of Senior Search for Extra-Terrestrial Intelligence Institute (SETI) Astronomer Seth Shostak, speaking at last week's European Commission Innovation Convention. Like many others in the scientific community, for Dr. Shostak the question is not if we will discover alien life, but when.

Dr. Shostak says the search will end in one of three ways. First, we could life microbes on Mars or Europa. Second, we could find gasses in the atmospheres in far-off worlds produced by life's processes like photosynthesis. Lastly, we could find signals of alien life through stations like SETI.

Shostak believes we won't have to wait until 2099 to discover life elsewhere. The next 25 years will give us enough time to probe our neighboring space for microbial life.

Or by that time, we could be found by some other intelligent life form too.